During the last two years of WWII, the Wehrmacht of Nazi Germany was slowly retreating from the eastern front, pushed back by the mighty blows of the Red Army. The bombing runs carried out by the western Allies from airfields in Britain were systematically hitting most urban centers in mainland Germany and over the territory occupied by the Nazis. It is hard to imagine, but it was in the year 1944, when the destiny of Germany was almost sealed, that industrial production in Hitler’s Third Reich reached an all-time record.
At that time the Germans were desperately short of fuel, raw materials and troops, and their production efforts would not spare them from a complete defeat in 1945. Yet it was in the last stages of the war that some of the most ambitious industrial facilities were designed, built and in some cases made operative before the end of the war.
The driver of the design was in most cases the need to move production lines to secluded and well protected areas, difficult to spot and to destroy through air bombing. As a result, these sites were placed far from urban centers. They were also designed to withstand bombing, by putting them underground, or building them with substantial reinforcement, making large use of one of Nazi Germany’s favorite materials – reinforced concrete.
In this chapter two major sites of this kind are described. One is in southwestern Poland, a region which had been part of the German Empire for long before WWII. The second is in eastern Bayern, today one of Federal Germany’s most prosperous states, close to the border with the Czech Republic. Photographs were taken in late summer 2018.
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Construction around this cluster of underground sites started in late 1943, and reportedly lasted until the closing stages of WWII, just days before the Soviets entered the region. The name ‘Riese’ means ‘giant’ in German, and it is surely well suited for this complex, which while far from finished is really striking in size. It was actually composed of at least six major construction sites, which in the intention of their designers should have been developed deeper in the mountains, until a link could be established between them forming a formidable network of tunnels and large halls.
Besides the size and historical meaning of these sites, what makes project ‘Riese’ so fascinating is also the actual purpose of this incredible complex is far from established. Three major theories exist in this respect. The complex might have been intended to be an underground industrial city, a kind of Noah’s Ark for the ‘superior race’ embodied by the top-ranking military and governmental staff of the Reich, or a gigantic secret laboratory for innovative technologies.
What is sure is that the construction was carried out by forced labor, mainly by prisoners of Gross-Rosen concentration camp, just a few miles north of the complex. For the scope, the Nazis created a number of satellite camps next to the entrance of the construction sites. Rather incredibly, only very scant traces of the project remain in the written records of key figures of Nazi Germany – Albert Speer’s personal diary notably reports some millions marks allocated for project ‘Riese’, and at some point after the war he cited the item resulting from the completion of the construction works, whatever its purpose, as sized to be capable of hosting some tens of thousands people.
Today, six construction sites have been discovered, of which two – Osowka and Rzeczka, the most conspicuous – have been opened to the public, whereas the other are visitable basically for speleologists only.
The first visitable site is in the town of Osowka. This site is composed of two parts, one underground with access from the side of a hill, the other close to the top of the same hill.
The underground part can be visited only with a guide. The plant of the completed construction features two accesses, and you will be driven in using the first and out using the other. Between the entrances, the site is mainly composed of an array of parallel tunnels pointing towards the mountain, connected by long halls.
Close to the entrance you can spot a concrete guardhouse with loopholes for machine guns. Some wooden structures like in a mine have been put in place to give an idea of the appearance of the working technique at the time of construction.
Most tunnels have been dug but not reinforced with concrete walls, whereas others are almost complete, showing a peculiar two-level design. The lower level features a smaller section, and the top one a taller, round shaped section.
A feature of the ‘Riese’ complex is a special technique for building the inner concrete coat of the rocky tunnels, producing the distinctive ‘church-ceiling-like’ appearance of some of the halls, with a round shape and frames close to one another.
The Osowka site features also a collection of smaller artifacts, collected from the ground and dating from the construction years, i.e. from late WWII.
Life-size silhouettes of some WWII tanks are on display, to show how the size of these items was totally compatible with the size of the tunnels, in support of a potential use of the site for weapon manufacture.
The outside part, which can be accessed freely, is the most mysterious. At the base of the trail leading uphill you can spot a strange concrete platform, with provision for – possibly – interred pipelines.
Close to the top of the hill you can find a huge concrete platform, with an apparently chaotic ensemble of slots, pipes, handles, stairs and pools. This item has been deemed close in shape to the base of a service building for the valves and pipelines of a power-plant. Theories have flourished in support of the use of this item as a prototype control system for a nuclear power-plant.
The nuclear program of the Nazis, which indeed existed and is even documented to some extent, is shrouded in mystery for what concerns the actual findings obtained during the war. These dark spots are also due to the destruction of most of the hardware connected with the program everywhere in Germany, and with the inherent secret nature of the program itself. No evidence exists of the Osowka site in the public papers about the nuclear studies of the Reich, so the true purpose of this object is likely to remain an unsolved riddle.
Close by this platform, you can find an original concrete building, part of the same construction plan. It is pretty long, with large windows, and likely intended for troops or technical staff.
Compared to Osowka, this site is more centered on the inside part. Again, there are two entrances, close by a creek on the side of a hill, providing access to a network of tunnels. Similar to Osowka, close by the entrance you can find guard-houses in concrete. These were built soon, possibly for keeping a watch on the forced workers.
The construction works in Rzeczka were less advanced than those in Osowka. Yet thanks to the lack of the concrete coat, you can appreciate the size of the tunnels, some of which are really tall.
There are small collections of artifacts found in the tunnels, and an original concrete room offers a description of all discovered sites of the ‘Riese’ project.
A 1:1 copy of a V-1 German flying bomb has been placed in one of the tunnels, to show the compatibility of the size of this weapon with the tunnel. Such weapons were reportedly assembled in underground facilities elsewhere in Germany.
Visiting is again possible only with a guide. Some multi-media experiences with sounds, lights and voices are included in the tour, but these are not so impressive for those who don’t understand Polish.
On the outside, you can spot some relics from construction years, including trolleys, and concrete slabs watermarked with symbols of the local construction companies tasked with the practical realization of the site. There is also a copy of a V-2 rocket, operative in the last months of WWII but little effective in changing the fate of Nazi Germany.
Getting there and moving around
As pointed out, the sites connected with project ‘Riese’ are many, but most of them are not visitable unless to specialists and with the help of a speleologist. On the other hand, the two sites of Osowka and Rzeczka are professionally operated as primary tourist attractions. The distance from these two sites is about 20 minutes by car, so you can surely arrange the tour of both sites on the same day, with much spare time in your daily schedule.
At Osowka you can find a large parking and a fully equipped visitor center, where you can book a guided tour, or join a departing one – the only way to get inside. Please note that the number of people admitted on each tour is relatively small, so I would suggest booking at least one day in advance through their website (partly also in English) to be sure to get a place at the time you like. They offer several different tours. The most complete include a visit to a part of the underground site which can only be accessed by boat. This is given only on some days by reservation, and only for groups. The standard tour of the inside is offered several times a day.
The guided may turn out really boring, cause you are provided an audio-guide in English with explanations lasting a couple of minutes for each of the circa ten stops, in face of the Polish-speaking guide talking about 5 minutes per site. You may try to spend your spare time taking good pictures, but even though groups are relatively small, they tend to obstruct the view inside, leaving poor chances for acceptable shots. Furthermore, lighting is not very good, so a tripod would be recommended, except you don’t have the time and chance for undisturbed long poses. Therefore, if you are interested in top-level pictures, you would better arrange a dedicated tour out of the normal touristic offer. Otherwise, you’d better go prepared to a difficult visit.
The outside part of the site is less frequented and more rewarding. It can be reached in about ten minutes following a pretty steep, unpaved trail in the trees. This part is unfenced and unguarded.
The Rzeczka site has only an inside part, which can be visited only on a guided tour. You can join one of the frequent tours they provide even without reservation. There is a small visitor center and plenty of parking space. Similar to Osowka, the guide will speak in Polish, and you are provided an audio-guide in English. The visit lasts less than in the case of Osowka, and the audio-guide explanations are more proportionate to the speech of the Polish-speaking guide, making for a more enjoyable visit. The multi-media experiences are of little relevance for non Polish-speaking people. Outside you can find also some panels with explanations on the history of the site in both Polish and English. Website with some info in English here.
The tunnels in Rzeczka are poorly lighted too, so photographing will be difficult unless with a tripod, but the conditions are not very favorable for operating with a tripod – many people around and short times between stops along the tour.
The giant complex known as ‘Weingut I’, the original codename attributed by the Nazi staff at the time of its design and construction, is the direct result of a plan to relocate all major industrial production lines of the Reich to protected areas, far from the line of the front and from any major urban center. In this particular case, the new factory was intended to shelter the production line of the new Junkers Jumo 004 jet engines for the ‘Schwalbe’ – also known as Messerschmitt Me-262, this was the first jet fighter in the world to be pushed into service, back in 1944.
The huge factory was designed based on a basic module made of a reinforced concrete arch, some 250 ft open, 100 ft tall and 10 to 15 ft thick. This item was to be built on site and partly buried under ground level. Twelve such modules were needed for the complete hangar, with a total intended length of the factory of around 1.200 ft. Of the planned twelve sections, seven were actually built between mid-1944 and the end of the war.
Despite the intended scope was that of hiding the factory to protect it from aerial reconnaissance, due to the size of the construction works the object was reportedly spotted by US aircraft, but not attacked. Actually, the special construction was tested against explosives by the US Army after the war, resulting in the collapse of all modules except one, which is still standing today besides the pretty sizable relics of the others.
The site is not actively guarded, but it is located in a regional nature preserve, so access is through a nice walk in the trees. Once next to the hangar you can find multiple access points.
Close to the main arch, the only one still standing, it is possible to find an explanatory panel in German only. It commemorates also the forced laborers from the nearby concentration camps, who had to take part substantially in the construction works.
Walking under the arch is at your own risk, cause despite the bulky appearance of the structure, smaller pieces of concrete are hanging from from the ceiling. However, a walk inside will give you the most striking impression of the size of the hangar.
Just nearby the remaining module to the west you can find a walkable, half interred bunker, likely with a technical function which is today hard to imagine.
The module still standing today is the westernmost of the hangar, so walking east you will have the chance to step on the roof of the demolished modules. A number of thick iron rods can be spot at ground level.
Walking along the former southern side of the hangar, you can spot a deep well, probably part of the construction strategy. It may have been used to take out the gravel from beneath the base of the arches to lower them to a rest position on more compact ground.
Along the same side you can find a way to walk below the fallen structure. You can also get a view of the edge of one of the modules.
The eastern end of the complex is probably the most hazardous, cause you find an unprotected concrete cliff a good 10 ft high, constituted by the edge of a fallen module.
All in all, the place is a nice example of the undeniable structural design abilities of the German military, really interesting to visit both from a technical viewpoint and as a witness of the utopian visions of the Nazis, which unfortunately cost the lives of many.
Getting there and moving around
Reaching the trail-head is very easy by car. Leaving Mühldorf am Inn for Waldkraiburg along the road St2352, about 0.5 miles south of the crossing with St2550 you will find a sizable gravel factory to your right, preceded by an unpaved road taking west in the trees. You can park on the unpaved road on the northern side of the factory – probably a heir of the original factory built to feed the construction works of the hangar.
From there, you should take the unpaved trail into the trees, closed to vehicle traffic. It is another 0.5 miles to the site, on a flat and easy trail. A quick scan of the Google map will allow you to plan the trip. The place is not remote, cell phones work and you may use a virtual map to get oriented on site. Visiting might take about 2 hours for a very interested subject, including the trip from the parking and back, plus all time needed for pictures .