Photo Exclusive: The Soviet-Designed Nuclear Shelters Hidden In Prague's Subway

This is the moment a 20-ton door, designed to withstand a nuclear blast, swung shut during tests at a subway station under the streets of Prague.

The door is a part of Prague’s Metro Protection System (Ochranny System Metra, or OSM), a network of hardened shelters designed to safeguard people during a nuclear, chemical, or biological attack. 


 

Engineers watch as the hermetically sealed blast door is closed over subway tracks. 

The OSM was built into Prague’s subway network beginning in 1974 when the specter of nuclear war was haunting Europe.


 

A subway train awaits its morning duties as a blast door is tested nearby.

Today, the Prague authorities describe the OSM’s purpose as both “to protect the population against the effects of weapons of mass destruction for a period of 72 hours," and “to isolate sections of the metro in the event of a major flood.”

A subway worker inspects a wall of air filter intakes in the OSM.

The network of shelters is designed to accommodate up to 320,000 people inside several specially equipped subway stations and the tunnels between them.



 

A ventilation fan in a room that workers say is deafeningly loud when the OSM is in operation. 

Josef Filip, the technical manager of the OSM, told RFE/RL the network of shelters was a state secret under the Soviet-backed communist regime in Czechoslovakia. “It was built during the Cold War and at that time it was under the control of the military,” he says.

A 2018 file photo shows a blast door inside the Soviet-era metro in Tashkent, Uzbekistan.

Prague's nuclear shelter network inside its subway is one of a handful of its kind in the world. Some sections of the subways in Moscow, Kyiv, and Tashkent (pictured) are also equipped to protect people from weapons of mass destruction. 

Air filters inside Prague's OSM which would be activated in the event the outside atmosphere is contaminated with radioactive dust or if Prague was hit with a biological or chemical weapon.

Some information about the OSM remains secret. The Prague City Transport Company requested RFE/RL not specify the subway station where these images were taken.


 

An air valve in the ventilation system of the OSM.

Filip says tests are made every night on the OSM to ensure its readiness. The transport company told RFE/RL the total cost to operate the system is hard to quantify but for "repairs and maintenance," around 80 million Czech crowns ($3.3 million) is spent per year.   

A ventilation corridor through a section of a Prague subway station.

Access to water inside Prague’s OSM comes through the city’s mains supply. The shelters also feature water storage basins that can be filled in preparation for an infrastructure collapse in the outside world.
 
 

Tanks that supply diesel to ventilation systems and electricity-producing generators inside an OSM shelter. 

No food is kept within the OSM. Filip says, “the expectation is that people coming down here in an emergency would bring their own things to eat.”
 

A sealed door inside the OSM that swings shut after the red light above the door begins blinking and an alarm sounds. 

Only some Prague subway stations are equipped to seal shut in the event of nuclear war. The Prague City Transport Company lists the stations on an interactive map, along with the subway tunnels between them that would serve as a refuge. 
 

A blast door at Prague’s Dejvicka metro station seen as a train approaches.

Most of the OSM was built during the Cold War, but updated versions of the Soviet-era system have been incorporated into some newer subway stations built by independent Czechia.

 
 

A subway worker walks through a wall of baffles designed to slow airflow within the Prague underground.

A spokesperson for the Prague City Transport Company confirmed that with the OSM's limited capacity of less than a quarter of the Czech capital's 1.4 million population, "it cannot be assumed that all residents will be sheltered in the metro" in the event of war.

 

Ventilation fans inside a Prague metro station.

 "Many residents will leave Prague before an armed conflict begins," The Prague City Transport Company spokesperson predicts. 
 

A bathtub and taps inside the Folimanka Shelter, an underground bunker in central Prague designed to house people in the event of a nuclear strike.

As well as the OSM, Prague has space inside a separate network of functioning Cold War-era nuclear bunkers, such as the one seen here, capable of housing around 150,000 people for the same 72-hour period as the OSM. 
 

Telephones inside the control room of an OSM shelter. 

The transport company in charge of the OSM says "a certain amount of time is required to put the protection system on alert," without specifying further.

A Prague subway station in the center of the Czech capital. 

"When the highest degree of readiness is reached, closing the shelter is a matter of a few minutes," the Prague City Transport Company spokesperson told RFE/RL, before adding, "it is not possible to use the metro to hide in the event of a so-called sudden attack."
 

Buttons on a desk in a control room of an OSM shelter. 

With the recent escalations seen between Russia and the West, one persistent criticism of the shelter system -- its cost -- has faded away.

A corridor beneath Prague alongside a public subway station. 

Before the full-scale Russian invasion of Ukraine, several senior members of the city council were pushing to have Prague’s nuclear shelters decommissioned. 
 

A door is closed during testing of an OSM shelter.

Today, arguments about shutting down Prague's network of shelters have fallen quiet. 
 

A Prague Metro station seen on December 5.

Several other European countries, including Czechia's neighbor Germany, are making active preparations to shelter its population in light of what is being called a "worsening international threat situation."