The Salpa Line – Finland’s Anti-Soviet Barrier

Possibly one of the world’s best preserved military installations from WWII, Finland’s Salpa Line – the name ‘salpa’ meaning ‘latch’ – is a defense line composed of about 700 reinforced concrete bunkers with anti-tank cannons and machine-guns, more than 200 miles of anti-tank obstacles, roughly another 200 miles of trenches pointed with over 1200 machine gun nests, 500 artillery positions and more than 700 quartering dugouts. All this, and everything necessary to operate this enormous war machine, including hundreds of miles of new roads, electric cables, dams, telephone lines, etc., was built to defend the border between Finland and the Soviet Union.

History – in brief

The Winter War

Finland enjoyed the rigors of WWII since 1939, when following the Ribbentrov-Molotov pact between Nazi Germany and the USSR, it was agreed off the records that this Country should enter the sphere of influence of Stalin’s communist dictatorship. Finding no other way to submit the Finns, Soviet troops attacked Finland from the East all along their common border, from the Gulf of Finland up north to the Barents Sea, at the end of November, 1939.

This rarely told chapter of WWII is known in Finland as the Winter War. Finland, which on a September 1939 map looked somewhat larger to the east than it looks today, fought fiercely against a numerically much superior enemy, which at the time was not engaged on any other major front. Despite the very difficult situation, with no help – except limited arm supply – from the outside, the motivated Finnish Army led by General Mannerheim recorded some marked victories especially in the central sector of the border, and managed to avoid a complete defeat. This unexpected military resistance, and the promise of Britain and France to support Finland had the war continued further, led the USSR to agree upon a peace treaty as soon as mid March 1940, basically crystallizing the military situation reached at the time. As a result, the border moved west by about 60 miles in southern Finland, with the loss of the Karelian Isthmus and the city of Vyborg, the access to lake Ladoga, Finland’s Eastern Karelia – simply known as Karelia in Russia – and a large territory in Lapland, mostly uninhabited. Finally, the peninsula and port town of Hanko, 70 miles west of Helsinki, was ceded to the USSR for 30 years.

Building the Salpa Line

It was at the end of the Winter War that Finland’s government, following the suggestion of General Mannerheim, took the decision to built the Salpa Line, to defend the new border against any possible attack of the Soviets.

Construction work on this impressive system, made not only of a chain of forts, dugouts and barracks, but also of an extensive network of communication and transport infrastructures, was carried out mainly between spring 1940 and summer 1941, Finland’s so-called Inter-War Period. Up to 35’000 workers – mainly civilians from private companies – were involved, roughly bringing the defense line to completion by mid 1941. The line was designed primarily to protect the most populated and easily accessible part of the Country in the south, and a major concentration of strong points was erected along todays border line with Russia, between the Gulf of Finland and the town of Joensuu.

At the same time, a smaller branch of the Salpa Line was erected on a much smaller scale on the new border with the USSR, along a 3 miles line cutting through the Hanko peninsula.

The Continuation War

In the period between the end of the Winter War and the surprise offensive of Germany against the USSR in June 1941, the Nazi Wehrmacht had successfully annexed Denmark and Norway to the Third Reich, thus becoming a neighbor state for Finland, just like the Soviet Union. In the process, Finland allowed Germany to transport troops and material to northern Norway moving on national land, and receiving arms in return. In the same period Hitler refused to endorse further Soviet attacks against Finland, thus further narrowing the diplomatic distance between Germany and Finland, which nonetheless managed to remain independent throughout WWII.

When the war broke out between the Soviet Union and Nazi Germany, Finland took the initiative and attacked the USSR, soon regaining control of basically all territories lost in the Winter War, including the port of Hanko, by the end of 1941. The German Wehrmacht attacked the Soviet port town of Murmansk and the nearby area, rich of natural resources, from the northernmost Finnish region of Lapland.

Due to the quick movement of the front line back east, the Salpa Line saw basically no fight, and was maintained until the end of the war with the Soviets in 1944 as a rear defense line.

This phase is known as Continuation War, and quickly turned into a war of attrition along a stable border line. This equilibrium was cracked when the military situation started to get worse for Germany after the defeat of Stalingrad in early 1943. After months of negotiations with the USSR to put an end to the conflict, following a massive Soviet attack on the Karelian Isthmus in August 1944 and the second loss of Vyborg, an armistice was signed in September between Finland and the Soviet Union, in favor of the latter. It restored the border line as it was at the end of the Winter War and imposed a long-term lease of Porkkala – a peninsula on the Gulf of Finland 30 miles west of Helsinki – instead of Hanko. Also included were heavy war reparations and the neutrality of Finland with respect to further Soviet campaigns. Plus the immediate expulsion of all German forces from Finnish territory.

Nonetheless, differently from almost any other Country touched by the Red Army in the events of WWII, Finland managed to retain its complete independence from Stalin’s communist empire, and part of the credit goes to the existence of the Salpa Line, a major deterrent against any further Soviet military aggression.

The request to severe any contact with Germany led to the final chapter of WWII for Finland, the Lapland War, when the Armies of Finland and the USSR attacked the Wehrmacht in the north of the Country, starting a campaign lasting months until the final defeat of Germany, causing the total destruction of many villages and of the town of Rovaniemi.

Sights

As a result of the course of events, Finland’s fortified line of defense did not see any direct military action. This spared it for posterity as a notable example of military technology of the Forties. Of course, as war technology evolved rapidly soon after WWII, the Salpa Line rapidly became obsolete and was largely abandoned. Most dugouts, soft construction works as well as most wooden, unreinforced positions have been reclaimed by nature. Only traces of the trench lines exist today, except in those spots where they have been explicitly preserved for the public.

Heavy positions are a totally different matter. Except for a few mainly in the northern part of the Country, blown up by the Soviets in the months of the Lapland War to help expelling Nazi troops from the Finnish territory, most bunkers and strong points are still there, basically intact. The majority has been abandoned, but due to a demolition work being an economy nonsense, they can still be seen today.

At least two small groups of bunkers in the very south of the Country have been turned into top-level museums on local military history, with a modern visitor center, guided tours and so on. Some bunkers, like in Joensuu, can be visited as little local museums. A good number of the reinforced concrete installations have been left open for interested visitors, stripped of any dangerous military hardware, sometimes even partly refurbished, and in most cases they can be freely accessed – provided you find them. Some are included as checkpoints along official multi-miles hiking trails, which are among Finland’s top tourist attractions. More often, either you know where they are in advance or you will hardly find them in the wilderness.

For reaching most of the non-advertised bunkers of the Salpa Line, you need to drive to very secluded locations along unprepared roads. If you like this kind of archeology, this adds much to the fun!

The good news is that Finland considers the Salpa Line a historical landmark as a whole, thus any damage or alteration is strictly prohibited and severely prosecuted. So you are not to see your search frustrated by finding a bunker covered in graffiti or used as a shelter by ravers or drug addicts – as it is often the case with the much similar Atlantic Wall in France. This is also because except for a few cases the superstite installations are located far from any urban center. By the way, Finland boasts one of the Europe’s lowest crime rates, so exploration is made potentially dangerous only because of intrinsic – rusty barbed wire, mimetic manholes, narrow passages, total darkness … – or natural causes – badgers, boars and bears!

In the following a description of a few notable points of interest along the Salpa Line is presented. The list is extremely far from complete, as it would take at least several months of dedicated work to explore the Line in its entirety! Yet this selection provides a good specimen of all basic types of sight you can find along the line. Photographs were taken during a visit in summer 2017.

Map

The following Google map was created based on the very useful information provided on this website, which is an excellent starting point for any exploration of the line. Basic info on the corresponding Salpa Line sites are provided on it almost one by one, and pinpointed on a map, but apparently there is no comprehensive map on that website. The website is also Flash-based and totally ‘iPhone unfriendly’ – it simply doesn’t load on my iPhone 6S. So I can’t take any credit except for having put together all points and having made them smartphone accessible. The red signals refer to points pictorially described in this article. The area of Hanko and the museums of Mikkeli are not covered in the map, whereas some sites will be described in another chapter.


The list below is ordered roughly from the south to the north.

Virolahti Bunker Museum, Virolahti

This site – Virolahden Bunkkerimuseum in Finnish – is among the southernmost of the Salpa Line, conveniently located on the busy E18 connecting Helsinki to St.Petersburg. The museum is a good starting point for getting an idea of the features of the line. There is a visitor center with a modern setup, where you can see a collection of light weapons from both the Finnish and Soviet sides – actually many Soviet weapons left behind by the retreating Red Army at the beginning of the Continuation War were later reused by Finland’s Army. Much information is provided in a synthetic and readable way – both in Finnish and English – on the construction of the line and about the war history of Finland, with a focus of what happened along the sector of the front closer to the Gulf of Finland.

The outside part is organized along a short trail in the trees. The first main stop is a reconstructed trench, with an example of a spherical soft concrete bunker type, conceived to cover dugouts. Nearby you can see two small heavy metal turrets. These were designed to be partly interred, to form an armored machine gun nest. The thickness of the metal construction is stunning! There is also a line of stones put in the terrain, a typical anti-tank obstacle to be found in many sites of the Salpa Line.

A German-made Pak-40, 7.5 cm anti-tank cannon in perfect condition is presented in a reconstructed open-top field fortification.

Nearby, you can access a perfect example of an anti-tank bunker. Three main areas are featured in this type of bunker. First, a relatively large living and sleeping area, with bunk beds for troops, a big stove, a water sink, and an air pump. Second, a firing room with a 45 mm anti-tank gun permanently installed, with the barrel leaning out of a suitably designed blind window. Third, a firing room with a machine gun, with the barrel leaning out of an open slot cut through the thick concrete wall of the bunker. Both the cannon and machine gun fire basically in the same direction, from the front facade of the bunker, whereas the only way in is through a sealed door to the back.

The bunker is provided with a metal observation turret on top, accessible through a ladder mounted in a very narrow vertical tunnel with a sealed door.

Another original bunker you can visit in Virolahti is a quartering bunker, capable of sleeping 40 people. The construction is similar to the large living area of the previous bunker, but this is larger.

Examples of original trenches which have not been refurbished can be spotted as smooth grooves in the ground between the reinforced bunkers. Finally, there is also a collection of cannons – some of them very old – and machine guns, from the USSR, Finland, Sweden, France and Italy. Heavy cannons from various ages were provided by France at the time of the Winter War, and put in place along the Salpa Line in more points, so they can be spotted pretty often in Finnish museums.

Not a part of the museum, it may be interesting to check out what the frontier with Russia looks like today. You can come pretty close to the border zone driving south of E18, along the unpaved Kurkelantie road going to the small villages of Reinikkala and Kurkela. There is a well signed respect zone instituted along the border line, which cannot be accessed without all necessary papers and permits.

Nonetheless, the striped posts marking the border can be spotted with a zoom lens from the distance. I can’t guess whether in Soviet times the border did look like this, or instead it used to appear less penetrable. Of course it may be just a matter of appearance – when I was there, I personally didn’t even think to try coming close to Russia without an explicit permission, so I don’t know what may happen should you try to get near the border by entering the respect zone by foot!

The Virolahti site can be visited in something less or something more than 1h, depending on your level of interest. It is flat and easy to tour, with a large free parking nearby. Website here.

Salpa Line Museum, Miehikkälä

This is probably the biggest exhibition on the Salpa Line, and the most visited also. The visitor center proposes a series of itineraries for touring the site on a self-guided base. The highlights are anti-tank and machine gun bunkers, a plane spotting wooden turret, trenches of various types, cannons and more. Together with Virolahti (above), it is surely a place to be if you want to capture at a glance what the Salpe Line is all about.

The Miehikkälä site is unique in its own respect due to the morphology of the territory, with a rocky cliff prospecting on an area of wavy land. The two main armored positions with an anti-tank gun and a machine gun are atypical, dug deeply in the rock, accessible from the top of the cliff, with the barrels leaning out at the level of the surrounding terrain. The bunker with the anti-tank gun features an observation/firing turret directly accessible from the firing room through a very long vertical passage. In the living quarters there is a collection of rifles.

The bunker with the machine firing chamber presents preserved sleeping and living quarters, and an observation turret.

Ahead of the rocky cliff you can find two armored turrets like in Virolahti, and an example of the most typical anti-tank barrier of the Salpa Line, made of aligned big rocks put in the ground. This is a distinctive feature of the Salpa Line, and following the rocks may help to find the location of more secluded bunkers in other sites.

Another interesting item is an old Soviet T-34 tank with the corresponding shelter.

To the back of the cliff you can find a German-made Pak-40 anti-tank cannon in an open-top field fortification. Looking in the direction of the barrel, you can see a long grove aligned with it. This is a tank trap, where the tank was forced to slow down trying to cross the grove right on the line of fire of the anti-tank gun.

In a second part of the site it is possible to find a group of rare concrete trenches, mostly similar to WWI constructions you can find in northern France (see this post), a housing bunker with a water reservoir on top and a standard anti-tank/machine gun bunker. These could be seen only from the outside when I visited.

The museum is not difficult to find, and there is a large free parking on site. The visit may take from less than 1 hour to more than 2 hours, based on your interest. While not difficult to tour for an average physical condition, you’d better go prepared to climb many stairs, move along narrow passages and walk short trails going steeply uphill. Website here.

Hostikka Site

The Hostikka site, deep in the countryside north of Miehikkälä, is composed of a handful of bunkers scattered a few miles apart along the roads in the municipality bearing this name. On each site there is a complete description in Finnish and English, and a map. Most sites can be freely accessed, a few are normally closed and can be opened on request, usually visiting with a ranger. A comprehensive map in Finnish can be found here.

From the south, item B186 is a massive anti-tank/machine gun bunker which is normally closed. The guns can cover a flat field ahead of the facade of the bunker.

A bare 300 ft north along the unpaved main road you meet B182, a machine gun bunker which can be toured freely. You can recognize the sleeping quarters and the observation tower. Climbing on top, you can appreciate the mimetic installation of the bulbous top of the armored tower. There is also what appears to be a firing hole close to the main sealed entrance.

All armored doors are still there, together with an extensive piping system.

Driving north for about 0.3 miles crossing the small village of Hostikka, you can find another site, with a preserved trench system, a machine gun and quartering bunker, open but unfortunately severely flooded, and item B166, a huge cave. This is not the only cave excavated in the rock along the Salpa Line. This multi-entry cave was intended for sheltering 80 people and providing access to open-top cannon/machine-gun dugouts. It was never finished, it is uninsulated and very wet.

The road going to Kirppu passes by items B150 and B132, standard anti-tank/machine gun bunkers. They are usually closed, but can be climbed and walked around.

All these bunkers unwind along a north-south direction, and are easily accessible parking nearby each site. Visiting may take 15 to 30 minutes for each open site, especially if you want to take pictures inside, less for closed bunkers where you may want to have a walk round. For inside pictures a tripod is mandatory, and a torchlight highly recommended.

Lusikkovuoren Cave

This cave can be reached driving for less than a mile on a secondary road departing eastwards from 3842 in Suo-Anttila. The cave is usually closed and sometimes used for public exhibitions or performances – a very suggestive location! -, yet the place deserves to be seen also from the outside. There are actually two neighbor entrances to the cave, which has been carved deep into the rock at the base of a cliff. The cave, intended to be used as a logistic interchange point, a headquarter and a weapons storage, was never completed. There are draining holes and a concrete pavement inside.

Hidden in the trees, far from any village, from the outside the cave really looks like a location from ‘The Lord of the Rings’!

Askola Site

The Askola site can be spotted while driving roughly halfway between Luumäki and Lappeenranta, along a busy road called Lappeenrannantie, next to the shore of lake Kivijärvi. There is a parking area just ahead of it. Heading straight to the big bunker you see from the road, you can find a map of the site. There is an uncommon concentration of armored positions in a small area between this trail head and the newly built highway N.6 to the south.

Despite the majority of the bunkers being normally unaccessible, there are some interesting uncommon sights here. The first is a reinforced dugout, where one of the bulky armored metal turrets you can see in the museums of Virolahti and Miehikkälä is interred in its intended working position. The turret can be accessed from behind and below, and a machine gun is mounted inside.

Furthermore, there are at least two original tank turrets recycled as reinforced firing positions. These turrets are apparently from BT-7 Soviet tanks, probably lost to the Finnish Army during the Winter War or the Continuation War.

More standard bunkers and dugouts can be found, but in some cases they can be barely neared due to wild vegetation.

About 0.8 miles to the west along the Lappeenrannantie road, you can find a small concrete dam – actually it lies in the courtyard of a private house… This is part of a system made to control the water level in the lake for military purposes.

Moving eastwards towards Lappeenranta, in the small village of Rutola it is possible to find another machine gun/housing concrete bunker, with an anti-tank barrier on the shore of the lake. This also lies on private land.

A visit to this site may take a 1-2 hours or more, depending on the level of detail and your ability to move around.

Syysphoja and Puumala Site

Along the beautiful scenic road 62 going from Imatra to Mikkeli it is possible to find two easily accessible forts of the Salpa Line. The first is located on Salpalinjantie road, departing north from the main road east of the village of Syyspohja. The facade of this well deceived anti-tank/machine gun fort, dug in a pile of land and hardly visible from the distance, is partly covered with stones. There are also partly refurbished dugouts and wooden obstacles, plus a long line of anti-tank stones.

West of the village along Töntintie road – very narrow and unprepared – it is possible to find a small Soviet monument to war prisoners interned in a local prison camp.

Another preserved bunker can be found right in the center of the nice village of Puumala, along road Pappilantie. The bunker is basically unaccessible, but very easy to walk around. In a receptacle besides the main entrance there is also a Soviet anti-tank gun, probably captured by the Finnish army.

General Mannerheim Headquarters and Communication Bunker

Among the highlights of the lively town of Mikkeli, you can visit here the preserved headquarters of the Finnish Army. The office of General Mannerheim and other top-ranking military staff, plus a fully equipped ‘op-center’, were installed in a local children school. Today a few rooms, including one with many original maps and Mannerheim’s personal office, are the ‘main course’ of the museum, and can be visited.

There are also informative panels, many pictures and some memorabilia belonging to General Mannerheim.

Almost cross the the road from the entrance of the headquarters, you can find another strictly related museum. It is a cave were the communication central of the headquarters used to be and work during WWII. This ensured an uninterrupted communication link not only with the Salpa Line but also with all positions on the line of the front. A part of the cave has been carefully refurbished to resemble what it looked like in the years of operation, including much communication hardware from the time, whereas another part has been left empty.

Both museums can be visited according to the respective timetables (website here for the headquarters, here for the cave). Total visiting time for both attractions is about 1.5 hours.

Raikuu Site

Two Salpa Line sites are located close to the small village of Raikuu, both easily reachable driving on reasonably prepared, unpaved roads.

The first is a massive and pretty rare heavy artillery position. There used to be four such positions scattered in the nearby area, two equipped with 299 mm mortars, two with 152 mm naval cannons. This is the only partly refurbished position. The base for the central revolving pinion where the cannon was anchored can be clearly seen, as well as rooms for the cartridges and for artillery troops.

The second is a group of three reinforced concrete bunkers, maintained to a very good condition and different from one another. The first two are a machine gun and an anti-tank cannon bunker respectively. The military equipment has been taken away, but the different shape of the barrel hole and the supporting structure for the machine gun or for the anti-tank cannon make them easily distinguishable. The machine gun bunkers bears traces of camouflage on the front facade.

Some of the original ventilation pipelines are still there, and clear traces of the wooden structures can be seen on the walls.

The last bunker is partly accessible from behind descending along a steep staircase. This bunker is leaning on the side of a rock, and is well deceived in the bushes.

The site is completed by an anti-tank wall of unusual construction, made of smaller stones put together to a very big overall thickness.

This site is very nice to visit, it is pretty remote so probably you will stay alone and undisturbed. Total time for visiting both including transfer by car may be 1.5 hours if you want to take pictures, or much less if you just want to have a look around.

Joensuu Bunker Museum, Joensuu

The museum in Joensuu is somewhat smaller than those in Virolahti and Miehikkälä (above), and when I visited it was already closed for the season – in mid-August! The good news is that in case you find it closed, you will miss only a visit to the inside of the bunker, pretty standard and similar to those you can see also elsewhere, whereas the outside can be toured for free at any time.

The first sights are two Model 1877, 90 mm French field cannons provided in a number during the Winter War and extensively used in the following years. Close by there are some steel turrets for protecting dugouts to form armored machine gun nests. These turrets, similar to those you may see also in some other Salpa Line sites, were supplied in very limited numbers and were produced in two shapes – you find both here – and three different weights. Those presented here are all intermediate-weight exemplars, weighing more than 5 and almost 8 tonnes respectively for the round shaped and the two-lobed model. The thickness is incredible, and these turrets could withstand a direct hit of a 45 mm anti-tank gun!

On the perimeter there is a Soviet 45 mm anti-tank cannon in a wooden open-top field fortification.

There are two concrete bunkers, put side by side on a promontory. One is equipped with both an anti-tank and a machine gun, the other only with a machine gun.

There are also well preserved dugouts and a line of rocky anti-tank obstacles.

The site is easy to access, with free parking, and compact in size, so less than 1 hour is needed for a visit if the inside is not accessible. Some opening info here.

Huhmarisvaara Artillery Position

Many cannons of French design can be found scattered over the Finnish territory. Except relatively few offered by the French at the beginning of WWII before France was conquered by the German Wehrmacht, the majority are actually Russian cannons from before the the Revolution. When turmoil started to spread in Russia in 1917 leading to the anticipate end of WWI, Finland took the initiative and declared independence from the agonizing empire. As a result, many weapons and military stuff stationed over the territory of the newly constituted Nation were recycled by the Finnish Army.

Many such cannons were later to be placed in the fortifications of the Salpa Line. In Huhmarisvaara, roughly 13 miles north of Joensuu, a concrete fortification for a number of cannons was prepared on a vantage position overlooking a local lake. One of the three Russian-made Model 1892, 152 mm cannons remaining in Finland can still be found in this location.

Vanntajankannas Site

The northern part of the front saw an active participation of the German Wehrmacht in the years of the Continuation War. Possibly one of the northernmost heavy installations of the Salpa Line was located about 5 miles southeast of the town of Kuusamo, close to the administrative border with the Lapland district. The Germans – with the forces of the Organization Todt – built also a railway line about 85 miles long in a north-south direction, with the northern terminal in Kuusamo. The railway helped to supply the army groups operating locally.

The history of this installation, today preserved as an open-air museum with a well maintained walking trail about 3 miles long, is a bit different from others. Soon after the armistice which drove Finland out of the war with the USSR, the German forces, which had to be expelled from the Country, started retreating north towards occupied Norway. They found shelter in the fortifications of the Vanntajankannas site for a few weeks, before loosing them to the Red Army. Soviet soldiers were forced to leave by the end of 1944 in accordance with the armistice agreement, but they blew up every hardware in the Vanntajankannas area before retreating to the USSR.

What can be seen here is what remains of some big concrete bunkers, of the types you can find elsewhere along the Salpa Line. The remains of the bunkers are scattered along the trail. Close to the trailhead there are also scant remains of the local railway station along the German-built line going to Kuusamo.

The anti-tank line of stones is still clearly visible. In many points the trenches, open-top passages and soft machine gun nests have been refurbished to look like the early Forties when they were built.

In the most remote part of the site it is possible to spot remains of the original concrete preparation station, used to supply the construction works, and a small concrete sauna for workers and troops – not really welcoming in these days!

This site is very nice not only for war history but also for the beautiful landscape, with incredible colors. You can also experience a walk over the marshes typical of this region of Finland. The trail is easy, there is a small free parking nearby the trailhead. I would recommend about 1-1.5 hours to enjoy the hiking trail and taking pictures of both the landscape,  the destroyed forts and preserved trenches.

Harparskog Line, Hanko Peninsula

The southern branch of the Salpa Line, also known as Harparskog Line, is composed of a group of bunkers concentrated in the small area around the village of Harparskog – on the Hanko peninsula -, which found itself on the border with the USSR for the first time following the peace treaty ending the Winter War. The annexation of Estonia to the USSR and the control of the Hanko peninsula gave the Soviets the control of the Gulf of Finland, which culminated in Leningrad to the east.

Hanko was evacuated by the Soviets in late 1941 during the victorious phase of the Continuation War.

Similarly to the rest of the Salpa Line, the smaller line in Harparskog featured all types of heavy concrete bunkers, plus dugouts, field fortifications and trenches. Today you can find at least one of the bunkers preserved as a local small museum, plus plenty of barely maintained but mainly accessible bunkers, stripped of most military hardware but still in a very good condition.

The bunker museum was closed when I visited, so here you have a view of the outside only.

Some of the accessible bunkers are aligned along an unpaved road towards the northern shore of the peninsula, north of the village. A commemoration stone with an explanatory panel clearly marks the trailhead.

Besides some more standard bunkers, it is possible to find here a big assembly composed by at least two large bunkers excavated in the stone. The passages leading to the entrances are carved deep in a local cliff, resulting in a very suggestive fort, a mix of natural and artificial defensive positions. Inside this fort it is possible to see also an original stove, ventilation ducts and an air pump.