Exploring Prague’s Hidden Cold War Bunker: The Folimanka Underground Shelter
Hidden beneath the eastern part of Folimanka Park under the high Nusle Bridge, lies one of Prague’s most fascinating Cold War sites — the Folimanka Underground Shelter.
I was lucky enough to be able to visit one cold winter day and spend a good hour or so exploring this underground shelter. Inside it’s a bit of a maze of concrete corridors and rooms filled with original equipment — old filtration units, emergency supplies, and even the diesel generator that once powered the entire bunker.
The shelter is only open once a month (usually the second Saturday of each month), but if you are interested in post war history, it’s definitely worth visiting.
What to see inside
The viewing of the shelter is usually free – flow, which means that you can walk around at your pace and take your time to see everything. I found rather refreshing, that there were no direct signs which way you ment to walk, you literary can go anywhere where there is no closed door. The only thing you need to worry about is to come back the same way as there is only one entrance (and exit).
You will be able to walk the long tunnels and look around most of the common areas. You pass through heavy blast doors into rooms that still hold their original equipment — filtration and ventilation units, oxygen tanks, and a surprisingly large diesel generator that once powered the entire facility.
There are maps and diagrams showing evacuation routes, civil defense posters, and even mannequins in gas masks that give you an idea what it was like to live during the Cold War.
Some sections are set up like small exhibits, while others remain untouched, with rusted pipes and old electrical panels left exactly as they were. I even found old shower rooms and toilets.
I should also mention that the few descriptions and display boards are only in Czech language. There are usually no official tours of the shelter, but if there are they will also likely be in Czech only.
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Folimanka Underground Shelter History
The shelter’s original construction plans date back to 1952, when it was built and operated under strict secrecy during the early years of the Cold War. According to archival records, construction was completed in 1962 at a cost of 5,912,240 Czechoslovak crowns.
Part of the structure incorporates a World War II–era tunnel, which originally served as a civilian air-raid shelter during bombings of Prague.
Folimanka is part of a citywide network of over 700 civil protection shelters built across Prague between the 1950s and 1980s. These were designed to protect civilians from nuclear fallout, chemical attacks, or conventional bombings. Folimanka is one of the largest and best-preserved of these shelters.
The bunker was classified as “Strictly Secret” (Přísně tajné) until the early 1990s. Even local residents living above it were unaware of its full extent or purpose. Only authorized personnel from the Civil Defense Command (Civilní obrana) could enter.
In 1994, the bunker came under the administration of Prague 2 District, which later opened it to the public in 2014.
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The shelter Technical description
The Folimanka Shelter is a tunnel-type civil defense bunker of the third resistance class built roughly 20 meters underground. Its deepest point, around 25 meters below ground, includes an emergency exit leading into the dome above.
The shelter was constructed from solid concrete blocks and all the facilites are on one-level. The shelter has several wells, two toilets, a decontamination room, an infirmary, two oxygen stations, three filtration and ventilation units, two dust chambers, two temporary morgues, a communications room, and an energy center.
At the heart of the bunker stands a three-cylinder 32 kW diesel generator from 1955, capable of supplying electricity, lighting, water, and air filtration in case of emergency. The shelter is fitted with armoured doors, one main entrance, two emergency exits, several escape hatches, and an observation post.
The building covers an area of 1,332 square meters and could accommodate up to 1,300 people for up to 72 hours without outside support. This is because it has its own water wells, filtration systems, diesel generator, and air purification units capable of removing radioactive dust and chemical contaminants.
In addition to the main entrance on Pod Karlovem Street, there are two emergency exits and several camouflaged hatches leading into the hillside and park above. Some are disguised as maintenance shafts or small utility structures.
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The Shelter That Never Had to Be Used
Despite its size and complexity, the Folimanka Underground Shelter was never actually used during a real emergency. Built in the tense years of the Cold War, it stood ready for a nuclear strike that, thankfully, never came. For decades, it remained sealed beneath the park, maintained quietly by civil defense workers who hoped their work would never be needed.
Former technician Jaroslav Havel, who worked for Prague’s Civilní obrana (Civil Defense) in the 1970s, recalled in an interview for the Prague 2 archives:
“We checked the systems every month — the filters, the generator, the water tanks. Everything had to be ready within two hours if the alarm ever came. But deep down, we all hoped it never would.”
The shelter’s massive diesel generator was occasionally started up during drills, filling the tunnels with the smell of oil and exhaust. Civil defense teams practiced sealing the doors and switching to internal air supply, simulating what would happen if the city above were contaminated.
“It was strange,” remembered Marie Kovářová, a civil defense volunteer who took part in several exercises in the 1980s. “You were underground, cut off from the world, pretending the city had been bombed. Even though it was only a drill, it felt uncomfortably real.”
When the Cold War ended, Folimanka’s purpose faded quietly away. The shelter was declassified in the 1990s and, for years, sat unused — a relic of a fear that had passed. Yet, as one former maintenance worker put it:
“We built it hoping it would never be used. And in that sense, it was a success.”
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Folimanka link to the Dan Brown latest book – The Secret of Secrets
In The Secret of Secrets, which is set in Prague, Dan Brown uses Folimanka Underground Shelter as one of the main places where a lot of the story happends. I started to read the book when I was in Prague, so it felt only fitting to take a photo in front of the entrance of the shelter.
In the story, the bunker—sealed since the 1960s—is revealed to house a secret laboratory linked to an ancient manuscript known as The Book of Secrets, a text said to contain formulas for unlocking human consciousness.
When protagonist Robert Langdon and Czech cryptologist Eva Nováková descend into the shelter’s echoing corridors, they find not only relics of the communist era—diesel generators, filtration rooms, and rusted command panels—but also a trail of modern clues pointing to a scientific conspiracy that bridges alchemy and quantum theory.
Brown uses the real architecture of Folimanka—its narrow tunnels, steel blast doors, and emergency domes—to heighten tension during a pivotal chase sequence. The shelter becomes both a physical maze and a metaphorical one: a place where Cold War secrecy meets the timeless human pursuit of forbidden knowledge.
Practical information for visiting
- Location: Pod Karlovem Street, Prague 2 – Nusle
- Opening: one Saturday per month, 9 AM–3 PM (usually second Saturday)
- Admission: Free
- Managed by: Prague 2 Municipal District (Městská část Praha 2)
Please make sure you wear sensible shoes (e.g. trainers) and clothes as the tunnels can be little uneven and you will be stepping in and out of different rooms with not always perfect floor surfacing.
How to get to Folimanka Shelter from the centre of Prague
Option 1: By Metro & Walk
Total travel time: 30 minutes (includes 1 km walk)
From Old Town Square (Staroměstské náměstí) walk about 5 minutes to the Můstek metro station (at the bottom of Wenceslas Square) and take take Metro Line C (Red Line). Transfer to Line C at Muzeum station (the next stop on Line A) and travel to the direction of Kačerov or Háje. Get off at Vyšehrad station (2 stops from Muzeum).
Afterwards it’s about 15 minutes walk (about 1 km) by walking downhill along Na Bucance Street towards Nusle. Continue along Sekaninova Street, which will lead you to the southern edge of Folimanka Park (you’ll see the large concrete Nusle Bridge overhead).
Option 2: By Tram
Total travel time: 30 minutes (much shorter walk)
This is a great scenic route and usually my preferred way to travel around Prague. From the Old Town Square, walk up to the middle of Wenceslas Square to the tram stop called Václavské náměstí and take Tram 6 heading toward Náměstí Bratří Synků or Spořilov. You can also take tram 11 from the Namesti Republiky (or the top of the Wenceslas Square, but it’s a bit further to walk).
Get off at the stop Pod Karlovem and the entrance will be on your right hand as you turn into the Pod Karlovem Street.
How to find the Entrance
The main entrance to the Folimanka Shelter is right opposite the houses on Pod Karlovem Street.
You’ll see a low, concrete structure with heavy steel doors set into the hillside — this is the bunker entrance with “Kryt Folimanka” written above the door and usually the next open day is chalk up on the door.
On open days, you’ll see volunteers or staff at the entrance and possibly a small queue of visitors.
This blog post was originally written on 6 October 2025 and last updated on 6 October 2025
