The Wollenberg Bunker – Linking East Germany and the USSR

Heading to Berlin or the former GDR? Looking for traces of the Cold War open for a visit?

A Travel Guide to COLD WAR SITES in EAST GERMANY

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The events taking place on the geopolitical stage during the last decade of the Cold War – the 1980s – gave little indication of the imminent collapse of the Soviet-led Eastern Bloc (1989-1991). Correspondingly, looking at the amount of technology developed and deployed in the military field during the late, hi-tech stage of the Cold War, it is easy to notice that opponents on both sides of the Iron Curtain dedicated a significant (and even increasing) budget in preparation for a possible total confrontation. Reading papers and specialized books from the time, the outbreak of an open conflict, such to put a violent and abrupt end to years of opposition between the two opposing systems by recurring to nuclear warfare over the territories of Western Europe (most of them belonging to the NATO alliance, and all being substantially more militarized than today), was not deemed just likely, but more as a matter of time.

The БАРС system – The tropospheric network of the Warsaw Pact

In that era of extreme tension, it is not surprising that one of the most sophisticated and expensive assets developed and deployed jointly by all Nations in the Warsaw Pact, of course led by the USSR, came alive. History would cut its life short though, and as soon as the Warsaw Pact disintegrated, as a result of the opt-out from communist dictatorship of all Countries in Eastern Europe, this asset was decommissioned. This system was the tropospheric communication system ‘БАРС’, a Russian word reading ‘BARS’ and meaning ‘snow leopard’. The name stands as an acronym for four words in Russian, which translate into something like ‘Sheltered autonomous radio communication system’.

The idea put forward by the Soviet top-ranking military staff in the early 1980s (prior to the onset of Gorbachev administration) was that of a system capable of transmitting complex orders (not just simple signals, like for opening a bunker door or silo, but articulated messages) in a safe encrypted way, at a long distance and minimizing the chance of a complete breakdown even in case of an enemy nuclear attack. Despite being not new, the concept of a resilient and reliable system, such to allow exchanging significant amount of data without relying on cables, had been tested in earlier stages of the Cold War only for short-radius operations. Mobile transmitters/receivers, loaded on purpose-designed trucks, allowed for a reduction of the risk of a direct hit from an attacker, and for a quick redeployment in case of need. However, for the amount of data and range required for the coordination of a war scenario, involving many different Countries, and geographically encompassing an entire continent, a different system was required, capable of transmitting more massive data flows on longer distances, with a reduced risk of a sudden or complete interruption.

The БАРС system was based on a certain number of stations, scattered over the territory of the Countries of the Warsaw Pact. Each node was built as a bunkerized, manned military installation, featuring high-power, high-frequency fixed antennas emerging from the ground, and an underground shelter protecting all the technical gear required for manipulating the data to be sent or received, interfacing with the other existing local (i.e. national) networks for military and executive governmental communication, and of course managing the tremendous amount of energy required to pump a long-reaching signal into the ether.

Laying on the front line with the West, hosting a Soviet contingent of some hundred thousands troops (see here and links therein), aircraft (see here), missiles (see here) and nuclear warheads (see here), and being a key-ally of the USSR in case of the outbreak of an open war (at least until late 1989), the German Democratic Republic (or GDR, or DDR in German) was clearly included in the БАРС network from the initial drafting phase. Similarly, Poland, Czechoslovakia, Hungary and Bulgaria, and of course the Soviet Union (which included Belarus and the Baltics, and stretched west to Kaliningrad), all had БАРС stations on their territory. Stations were located at a range of a few hundred miles from one another, thus within the range required for each of them to communicate with one or more of the other nodes. Data (e.g. orders, reports or authorizations) input locally could be relayed along the network through intermediate nodes, down to the intended destination node. There were 26 nodes in total, of which four were in the USSR.

The Wollenberg site – Bunker 301 ‘Tushurka’

The GDR in particular had three stations built, all along the border with Poland, and located east of Berlin – namely Station 301 in Wollenberg, at the same latitude of Berlin, Station 302 in Langsdorf, towards the Baltic coast, and Station 303 in Röhrsdorf (near Königsbruck), not far from Dresden in the southeast of the GDR territory. The first among them, the Wollenberg site (codenamed ‘Tushurka’) could communicate with the other two national stations, as well as with Station 207 in Poland, from where data would be transmitted further down the network, towards the USSR.

The site was built by the GDR state, with technical hardware coming from several Countries within the Warsaw Pact, and most of the military hi-tech components manufactured in the USSR. The actual site (similar to its sister sites) was built in the frame of a highly secretive operation. The staff comprised about 60-70 men, the majority of which were military, where about 15% were civil technicians. Maximum security clearance was required, due to the top-secret nature of the installation and of the overall БАРС system. The bunkerized part of the installation was only a component of the larger premises of the base, camouflaged within the trees on the side of low-rising hill.

As pointed out, the immense spending required for setting up this multi-national hi-tech military communication system, which was extensively tested and completely commissioned (as a network) by 1987, did not save it from a quick demise and disappearance. In particular, Station 301 went definitively offline as early as August 1990.

However, the fate of the Wollenberg site was not so sad as that of many former Soviet or NVA (i.e. the East German Army) installations in the GDR. The high-power antennas were torn down, but except from that, little material damage was inflicted to the buildings and bunker on site. The place was basically shut-off and left dormant, until when a society of technically very competent local enthusiasts started a plan to preserve and open it to visitors, as a memorial specimen of the technology of the Cold War years.

A visit to the Wollenberg bunker site reveals a tremendous deal of interesting details, very uncommon to find elsewhere in the panorama of Cold War relics around Europe. Thanks to a careful preservation and restoration work, the bunker has most of its original systems still plugged to the grid and lit-up – some of them are reportedly still working! Even though the communication networks have been severed, the experience in the bunker is really evoking, and the atmosphere – with all the lit-up cabinets, lights, CCTV cameras, 1980-style screens, etc. – closely resembles that of the bygone era when БАРС was operative!

This report and photographs were taken during a private visit to the bunker, carried out in the Summer of 2023.

Sights

A visit to the the installation in Wollenberg starts from the original high-security access gate. As you may quickly notice when passing through it and getting a first view of the site, the state of preservation is exceptional. Except for the lack of military staff around, everything looks mostly like in the years of operation.

A group of soft-construction service buildings and a reinforced multi-entry garage constitute the first – and visible – nucleus of the installation. All buildings are painted in a camo coat.

A former building for the on-site staff has been turned into a permanent exhibition, with memorabilia items from the Cold War years, when the Nationale Volksarmee (or NVA, the Armed forces of the GDR) cooperated with the Soviet Red Army and the national Armed forces of other Countries in the Warsaw Pact.

A meeting room, now employed also for small gatherings, is especially rich of interesting and diverse items, including emblems, books, memorial plates and pennants, as well as TV screens, hi-fi systems and and beamers from the era.

Another room has been set-up as a control center for the base, with an original console and regional maps.

Compared to military bases (for aircraft or tanks), the Wollenberg installation is rather compact, with a main road giving access to most of the (not many) buildings on site, as well as the bunker. Actually, the bunkerized part was built under a low-rising hill, with the antennas originally standing on top of it. Access to the bunker is possible either by climbing uphill on the main road, or through a suggestive original pedestrian tunnel. The latter starts from within the service building itself, and – somewhat unexpectedly, for an underground installation – it climbs uphill, while keeping beneath the surface of the hill side slope. The lower end is guarded by an original CCTV camera.

At the top end of the tunnel you can find the actual access to the bunker. The design and reinforcement level conferred grade ‘D’ protection according to the military standard in use at the time, with grade ‘A’ being the strongest. Access is through an airlock, constituted by two tight doors at the opposite ends of a small vestibule built in concrete. This design allowed protection from the blast of a nuclear device.

Notably, the locking mechanism of the tight doors is Soviet military standard, which can be found in high-value installations like nuclear depots elsewhere in the Eastern Bloc (see for instance here in Poland, and here in Czechoslovakia).

To the visitor with some experience of Cold War installations, it will be apparent from the very start of the tour that the state of conservation of the bunker, including the systems in it, is exceptional, similar to the rest of the Wollenberg site. The original warning lights and the CC-TV camera for identifying people at the entrance are still in place.

Next to the entrance, a control room with technical gear for checking-in can be found – including original dosimeters for radiation and chemicals, mostly Soviet-made. Looking inside these devices is possible, and reveals a great deal of sophistication in the design and realization of the military-grade material from the time.

Showers and sinks for washing, as well as canister for disposing of contaminated clothes, are located in the same area.

Upon getting access to the sealed area of the bunker and passing by the decontamination facility, you find yourself on the top floor of the underground bunker. The high-technology gear required for the transmission/reception of data on the БАРС network, as well as the interface with other national communication systems, required for receiving data, issuing orders, etc. over the territory of the GDR, were located on this floor.

Two symmetrically placed rooms host two twin transmission centers for the БАРС system. A single manned console can be found in each of them, surrounded by electronic cabinets and switches. At a closer look, all the material herein is Soviet made, and labeled in Russian only.

On the wall ahead of the console station is a set of cables, communicating with the antenna and allowing to set the orientation and monitoring its status.

The actual signals transmitted to the antenna, or received from it, traveled along special hollow ducts, with an almost rectangular section. Bundles of these ducts can be found in the ‘Sender’ (which means ‘transmitter’ in English) room, immediately next to the room where the manned console is.

The modulation and demodulation of the signals going out and coming in respectively through the antenna on top of the bunker required some special pieces of electronics, which included the Soviet-designed KY-374 klystron (codenamed ‘Viola’), a component to be found in the cabinets of the ‘Sender’ room.

Following the hollow ducts, it is possible to find where they finally exit the usually manned part of the bunker, bending into receptacles and leading outside. Piping related to other systems, including air conditioning, can be seen as well crossing or running in the same narrow technical corridors.

Beside the consoles monitoring the antenna and the data flowing through it, a kind of operative room for communication can be found, where consoles allowing to receive and forward data and communication to/from all systems are on display. This largely original room features consoles of different levels of technology.

Original explanatory schemes showing the basic features of the БАРС system are on display in that area – in Russian!

An adjoining room features the cabinets required for making all these system work. The cabinets are really many, with a significant share of material manufactured in the USSR. The sight of all these cabinets together is really impressive, and tangibly provides the feeling of a high technology, sophisticated and expensive design. It compares well, but in a largely up-scaled fashion, to the electronics to be found in some special communication bunkers on the western side of the Iron Curtain (see here).

Interspersed with the original arrangement of the cabinets and consoles are some displays of original material. These include specimens of different types of cables for signal transmission – some of them hollow and pressurized, others featuring impressive bundles of thinner wires – the KY-374 klystron, and other once top-secret core components of the БАРС transmission system. Also on display is one of the few remaining parts of the original system of antennas, once on top of the bunker. The antennas were the only part to be physically torn down when the system was decommissioned, upon the demise of the Warsaw Pact and the end of the Cold War.

The bunker was manned by military and technical staff 24/7. Furthermore, as typical for bunkers from the Cold War era, provision was made at a design level to allow the staff to live isolated within the bunker for an extended period of time, in view of the eventuality to face a nuclear fallout scenario.

On the same floor as the technical rooms, the commander of the station had his own private room. This is still adorned with typical Soviet iconography, as well as everyday material from the age when the bunker was operative.

A small canteen, with a kitchen and a modest living room, can be found at the same level. An original storage room has been employed to gather examples of everyday products, like soap, skin care cream, etc., as well as canned food, cocoa, and beverages of all sorts.

This represents a very rich catalog of now largely defunct and forgotten labels, from the age and regions of the Eastern Bloc (and especially from within the GDR). Also on display are bottles of spirits, likely still very good!

The visit proceeds then to the lower floor, which can be reached through a flight of metal stairs.

The lower floor host the plants required for the regular operation of the entire bunker, such to guarantee operational ability even in case of an enemy attack carried out with nuclear, chemical or biological warfare. The air filtering and conditioning system is very modern. Beside typical filtering drums for particles, to be found also in other bunkers (see for instance Podborsko here), you can see a bulky filtering and climate conditioning system, neatly arranged within two parallel square-shaped ducts. Filtering against chemicals as well as biologic agents was carried out employing special active filters.

Sensors for the level of contamination of the bunker air can be found in different rooms. Much material here is standard Soviet-made.

Systems for water pumping and compressed air can be found as well, including compressors, pumps and reservoirs. Looking at the always interesting factory labels in this area, it is easy to find export products of Bulgaria, Romania and other communist dictatorships of the era. Of course, much hardware is also manufactured in the GDR.

Electricity was supplied from the outside grid, yet capability for self-sustaining in case of a grid loss (for instance in case of war) was implemented as well. Three big German-made Diesel generators have been put in place, and are still in an apparently good condition.

Another example of the high technological standard reached in the late Cold War era is represented by the control room for the plants within the bunker. A manned control station, with a console and a direct view of lit-up cabinets, reporting the status of the various systems running in the bunker, compares well with control rooms of large industrial plants in operation today.

Carefully kept in its original status, with many of the electric links and cabinets still working, the sight of this room is especially evoking.

Also on the lower floor are the sleeping rooms for off-duty staff. Typically, this was not employed except for drills, when the bunker could be sealed to simulate operations in case of the outbreak of hostilities.

Back to the upper floor, it is possible to exit the bunker via a stairway and through a side gate. You will find yourself on top of the low-rise hill where the bunker has been dug. Here the concrete base of the crane where the БАРС antenna used to sit are still visible. Notably, these antennas were much smaller than the tropospheric antennas employed for the TROPOSCATTER system of NATO. This was the result of a different bandwidth employed for transmissions. Therefore, even in the days of operation, the antennas on top of the bunker were not as sizable as those of TROPOSCATTER installations (which were enormous in size).

Looking closely, in the top area of the installation, the duct for supplying the Diesel oil tank of the bunker can be found, similar to sensors for radiation and other atmospheric parameters (similar to what can be found also in other nuclear-proof bases, for instance here). These allowed to monitor the conditions of the outside air, detect an attack and trigger or manage the sealing of the bunker in case of need, by locking all the tight doors.

This access to the bunker is fenced by the original electrified fence, severing this area from the rest of the installation through a further layer of security.

All in all, a visit to the Wollenberg bunker offers an incredible insight in a fascinating and crucial field of warfare – data and communication exchange – as well as a lively and evocative display of a late Cold War hi-tech installation from the Soviet side of the Iron Curtain!

Getting there & Visiting

The German name of the Wollenberg bunker is ‘Militärhistorisches Sonderobjekt 301 Wollenberg’. It can be reached very easily with a car. It can be found in the open countryside along the regional road 158, driving about 35 miles (about 1 hour) northeast from downtown Berlin towards Poland. The exact location is between the small village of Höhenland (~4 miles) and the more sizable Bad Freienwalde (~6 miles). There is a large parking area immediately next to the road, giving direct pedestrian access to the premises of the former military installation. Despite being placed very conveniently, the site is rather elusive when passing by, since it is hidden in the trees and not directly visible from the road. The address corresponding to the place in Google Maps is Sternkrug 4, 16259 Höhenland. The inconspicuous village of Wollenberg, giving the name to the installation, is just nearby, but it is not crossed by the regional road, and it should not be employed for pointing this destination with a nav.

The Wollenberg bunker is a listed historical installation. It is perfectly maintained, privately managed, and it can be regularly accessed with guided tours. These are offered typically one day per week in the summer, or by prior arrangement. Possibly the best option for getting the most out of your visit is getting in contact with the group of very knowledgeable enthusiasts running the place. The official website is here (do not be discouraged by the ‘static’ appearance of the website, they are very active, and they shall typically answer your inquire).

My visit was planned by initiative of Dr. Reiner Helling (see also here), and we visited in a group of three, including the guide (Dr. Michael Schoeneck, a former engineer, with a profound knowledge of any technical aspects related to this installation), which happened to be a perfect option for touring also the narrowest receptacles of the bunker. Visiting in groups too big may be not advisable, since the rooms and corridors are rather narrow, and the place may turn overcrowded for interacting with the guide and for taking good pictures. I think the visit – including the technical content – may be tailored to the needs of the audience. For technical-minded subjects, historians and former military, a visit may take about 2-3 hours (the latter was my experience). In my case, the guide could understand but not speak fluent English, yet Dr. Helling could translate with ease all the explanations. Of course, if you have at least a basic knowledge of German and of the technical material you are looking at, this may simplify your visit, which is in any case highly advisable for those interested in military technology and the Cold War.

Heading to Berlin or the former GDR? Looking for traces of the Cold War open for a visit?

A Travel Guide to COLD WAR SITES in EAST GERMANY

Second Edition - 2024

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Bunker Kossa – A Preserved Cold War Military Bunker in the GDR

Heading to Berlin or the former GDR? Looking for traces of the Cold War open for a visit?

A Travel Guide to COLD WAR SITES in EAST GERMANY

Second Edition - 2024

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The history of the underground installation in Kossa-Söllichau begins in the 1930s under Hitler’s rule.

In 1935, an affiliated company of the German chemicals giant WASAG, named Deutsche Sprengchemie Moschwig and devoted to the mass production of explosives for warfare use, had a new plant built in the rather uninhabited forest area between Leipzig and Wittenberg.

The plant, codenamed ‘Beech’ (or ‘Buche’ in German), was updated over the years and turned into a major production center for several models of shells and high-explosive charges. A primary contractor of the German Army, the company also held relevant patents, including one for hollow charge grenades.

By the end of WWII in April 1945, when the area fell under Soviet control and production was halted, the plant counted 3.600 employees, and had a production capacity of around 600.000 ammunitions per month. It had been provided with a dedicated road and railway connection, and built mostly underground, with several concrete bunkers surfacing from the grassy terrain around.

Following the Potsdam agreement (July 1945), the area was completely flattened by the hand of the Soviets, similar to some other production facilities in Germany. Demolition had been completed by the end of 1947. Following that, the area remained silent for more than a decade.

By the early 1960s, with the Cold War and rearmament in full swing, the the Nationale Volksarmee, or NVA – the short name of the Armed Forces of the GDR – had been long established as an ally of the Red Army. The latter was physically present in Germany with a huge number of troops and war material, having taken over many of the former German bases from WWII (see here or here for instance). However, the GDR clearly had its own Armed Forces, which actually could count on high-quality war material, typically either manufactured in Germany or supplied by the USSR. More and more locations – especially the most secluded and easy to hide – got surrounded by fences, and ended under the control of the NVA for many different purposes.

Deployed on the border with the West, and considered a reliable and well-trained partner by the Red Army, the NVA was included in the war plans conceived in Moscow, intended to unfold in the event of an open war with the neighbor NATO Countries. The NVA had two larger military districts, south of Berlin (III) and north of Berlin (V). In case of war, district III would give birth to a 3rd Army of mixed GDR/USSR forces, to quickly push towards the south-west into Federal Germany (heading to Koblenz), and from there to the Atlantic coast, to be reached in a matter of a few days.

The headquarter of the 3rd Army was in the so-called ‘Mosel’ bunker, an underground command facility near the town of Zwickau, today converted for an alternate use and not visible at all.

An alternate control site, which was also primarily involved in drills and training, was built in the area of the former ‘Beech’ installation, and took the name of ‘Bunkeranlage’ (i.e. bunker installation) Kossa-Söllichau. This site was prepared in the years 1976-79, and consisted mainly of 5 large interred bunkers on the same premises, capable of resisting to tactical nuclear blasts, with up-to-date systems for communication, and an ability to replicate war situations, so as to carry out realistic and complicated tactical simulations and drills. The staff was typically of 400.

Similar to the majority of military assets in Germany – and especially within the super-militarized ex-GDR – Kossa was incorporated in the Armed Forces of reunified Germany (1990), but was soon declared surplus, deactivated and handed over for civilian use.

A society of enthusiasts is today running this former facility, keeping it open for visitors on a regular basis. What makes Kossa an exceptional destination for both the general public and the most committed war tourist as well is the great state of conservation of the entire facility. As it can be seen in the following photographs, taken in Summer 2022, inside the bunkers it is possible to see not only the original structure, but most of the original communication systems, paneling, signs, furniture, lamps, toilets, lighting, wallpaper, etc. making the place a very vivid testimony of the Cold War years.

All in all, this is one of the best surviving specimens of bunkerized NVA sites, and definitely worth a visit for a rich in detail full immersion in the military technology and history of the Cold War years.

Sights

A visit to the Kossa site will start walking past the original inner gateway to the bunkerized part of the complex. The original wall going all around the entire military area has been partly removed, allowing to get direct access to the ‘core’ of the installation by car. Traces of the electrified fence running all around this inner part of the complex are still standing. The entrance to a bunker for the guards can be seen in this area, but this cannot be visited.

The core of the complex with the military bunkers is aligned along a single, mostly straight technical road, built with large concrete slabs. The road track today is the same as in the original pre-WWII complex, and for this reason, it was not camouflaged. Other buildings in the complex, an even the connection roads departing from the main one, are painted in camo coat, for deception in case of overflight by plane or satellite.

The ticket office today is hosted in a large technical building by the entrance. In this area there used to be canteens and other services.

Past the entrance to the bunker area, it is possible to visit five bunkers, which will be listed next.

Computer Bunker

Four out of five bunkers (the exception being the intelligence bunker, see later) are built around the same blueprint. They have a single entrance door, deceived under a small wooden hut. Access to the bunker is via a security and decontamination path. At first you see a big camera at the level of your face, and an intercom panel, all for identification. Next follows a sequence of tight doors, at a close distance from one another, producing three small tight compartments.

In case of nuclear/chemical contamination, faced in wartime, in the first compartment you could take an anti-poison kit, EP-68. Exemplars of this are still in place. In the next compartment you had to throw away all your clothes and belongings, which were put through a hatch to the side. In a third small compartment, you found a shower – a central passage in the decontamination process, even in case of exposition to nuclear events.

Through a last tight door, you could finally enter the clean area of the bunker. Here regular toilets and showers can be found, before going down one level, to the technical part.

Back then, there used to be three levels of air sealing. No air sealing, in regular, no-war/no-drill conditions, meant the decontamination procedure was not activated, and the bunker was ventilated with fresh air. In sealing conditions, typically at war but not under direct attack, the bunker was tight closed, and air was pumped from the outside through huge filtering canisters, purpose designed to stop both smoke and other gases, or poisonous chemicals. On the third level of air sealing, corresponding to an emergency condition (e.g. a direct attack), no air was pumped from the outside, and special filters capturing carbon dioxide allowed to carry on for a limited amount of time – reportedly a shorter time than granted by food or water storage.

Filters for the air conditioning system (sealing level 2) and for adsorbing carbon dioxide (sealing level 3) were made in the USSR. Those for carbon dioxide are scattered around the bunkers, and feature a rather vintage Soviet look, with a prominent five pointed star on top. The label carry the assembly year, in most cases the early 1970s.

Once downstairs, you can appreciate the construction of the bunker lower level, based on prefabricated concrete frames. The bunkers in Kossa were capable of resisting blasts typically from smaller tactical devices, and were ranked at the fifth strength level (level ‘E’), the first level being the strongest.

Here a few rooms are still perfectly preserved with computers, of which the most impressive is a mainframe AP-3, working with magnetic tape. The GDR could boast a top-notch electronic industry within the Eastern Bloc, and all consoles and electronics in Kossa bear local labels.

The purpose of the computers, deemed so relevant to create a bunker specifically for them, was the fast elaboration of all information from the war theater. The latter was both local and global, since thanks to the links reaching the site through the intelligence bunker (see later), information of any kind could be elaborated, allowing the constant updating of operation maps, and the monitoring of all war assets. In drills, the computation capacity of the the system allowed to simulate events, thus forming the core of war-game operations.

A small part of the same bunker, a kind of mezzanine, was designed as a small hospital – all exhibits are original here as well.

More items on display in this area include original dosimeters and gear for checking radiation levels – either GDR- or USSR-made. In the connecting corridors are an intercom and an alarm horn – just examples of the perfectly preserved material on display.

Command Bunker

The command bunker shares the general arrangement with the computer bunker. A full anti-chemical/biological warfare suit is displayed by the entrance, ahead of the decontamination facilities. This type of suit should be worn over regular garments, and made for a very uncomfortable, ultra-warm and suffocating top layer, which reportedly caused extreme sweating.

The focus here is a control room, with a large table and an operation map, as well as connections through several lines to the relevant information networks. On one side of the control room are desks for telephone operators. On another, watches and chronographs. Also interesting are two TV-scopes, which allowed to plot useful information especially in case of drills.

Examples of maps for military drills are scattered all around. Since war plans were all variations on the same theme – a quick attack pushing to the west – all corresponding maps feature this type of planned motion, from within the borders of the GDR to the FRG. The name of the drills can be seen clearly stated on the maps – for instance ‘Grenzschicht – 81’ from 1981.

Other rooms on the underground level feature very interesting examples of machinery for translating information to/from paper maps, even physical 3D maps with elevation!

Satellite or spy-plane images of the site are on display as well. The site of Kossa was reportedly not far from the southernmost of the three air corridors reaching West-Berlin from the FRG. However, even though the site was not unknown in the West, its purpose remained largely a guess for the duration of the Cold War – and likely so also for the local civilian population.

Technical Bunker

A major concern in the Cold War was that of the survival of the chain of command in the event of a total nuclear war. This led to the implementation of additional on-site plants, for self-sustained operations in case a nuclear explosion nearby made the area unsuitable for human life, or when links with the surroundings were lost. These plants included primarily power generators, typically large Diesel engines with their fuel tanks, and drinkable water tanks. As seen in the computer bunker, also breathable air was a major concern.

In the technical bunker in Kossa, similar in shape to the previous two, at least two large power generators can still be seen – and smelt… – on the underground level. Several electric parts for replacement are also there. Another room hosts large drinkable water tanks.

An interesting preserved office for a commanding officer still retains its original GDR wallpaper, and additional comfort is provided by a fake wood pavement.

Large electric cabinets take a big room, where instrumentation for radiation measurement is on display nearby.

Other particulars include a dial telephone with a reminder of the quick reaction numbers, including the Volkspolizei – the name of the People’s Police of the GDR, which can be seen on a label!

Intelligence Bunker

The intelligence bunker is way larger than the others in Kossa, and is also more articulated. Access was possible via two bulky metal gates, located at an underground level on the far ends of the bunker, and reached through truck-sized ramps from ground level.

Behind the door, a tunnel of prefabricated concrete allowed to store many vehicles – typically trucks, jeeps and trailers, including vehicles with communication functions.

To the interred back of the tunnel, a human sized hatch gave access to the pressurized, tight area of the bunker. This inner area, completely interred, is surrounded by a concrete case, built by a single pouring to avoid the creation of weak junctions, and such to withstand intense blasts.

Following a tight compartment, with an array of original air-filtering canisters on display, you get access to a long corridor, providing access to some rooms with technical gears for communication. Here communication with different levels of secrecy were managed, accessing all the existing links implemented in the years of construction within the GDR, and between all Countries of the Warsaw Pact and the USSR.

A first room is centered on a large console, with an original teleprinting device still in place – top-notch for the time. Still in use today in some businesses, teleprinting is a very reliable way of communicating, which is also less prone to interception than telephone.

An adjoining room managed contact with three wired systems of communication, working at increasing levels of encryption security, and used for transmitting routine or less-standard orders. These systems included S1 and SAS communication protocols. The corresponding transmitters/receivers – now very rare pieces of machinery – can be seen on display.

Encrypted incoming messages were sent to a special room, where they were translated in human language, before being internally forwarded to the command bunker. Similarly, encryption facilities were all in another room, where outbound communications were made ready for transmission.

An impressive technical room is stacked with communication electronics. The number of components is really high, and reflects a very high performance, achieved by means of top level, but relatively bulky, components from the 1970s.

A room in this bunker is dedicated to the ‘BARS’ system (‘БАРС’ in Russian), a troposphere (i.e. not wired) transmission system within all States in the Warsaw Pact and with the USSR. Beside an indigenous transmission protocol, the system made use of purpose-designed antennas, with easily deployable nodes put on wheeled trucks. An evoking, very interesting map of the fixed nodes of the system, in Russian, can still be seen on a wall. The desks for the operators of the system are just besides.

Another interesting item is the control panel of a micro-wave antenna, installed in Kossa at a shallow underground level, in an area which can still be located, corresponding to an inexplicable grassy lot along the main road in the site. This antenna system was apparently never used, on grounds of energy consumption and potential damages to other systems in the Kossa site.

Back outside, close to the intelligence bunker are an original weather station, placed nearby a radiation detection system – looking like a bell bolted to the ground. Examples of connection roads covered in camo paint can be seen in this area. Along the main road of the site, many ramps give access to semi-interred lots, where technical trucks used to be placed for operations.

An example of these trucks is a Soviet trailer for enemy signal jamming. This is well preserved both inside and outside. The label tells the construction year – 1986.

Museum Bunker

The last visitable bunker is similar in shape to the former three, and has been converted into a collection of items from the history of the old WASAG site, the NVA bunker and the Cold War.

Propaganda items from the GDR enrich this interesting collection, as well as rare photographs from the totally gone ‘Beech’ site originally developed in the Third Reich years. Also on display are detailed designs of the weapons produced here in WWII.