MOSCOW – A secret network of nuclear bunkers dating back to the Cold War lies several meters below the streets of Moscow.

One of them, Bunker 703, has been opened to the public, with visitors now able to explore a maze of tunnels that served as an archive for secret documents for the Foreign Ministry of the Soviet Union.

“Come to see recently declassified facility of Cold War period,” a description on the website said.

“It was built at a depth of 43 meters just one year before the missile crisis.

“It was in use by the Ministry of Foreign Affairs until 2005, and inside, you will see an active 10-ton door that would have protected the bunker against the shock wave of a nuclear strike, as well as many hermetic doors that separate parts of the object.”

The website also warned that the bunker is “not a typical museum tour” and that visitors have to negotiate a 43-meter metal staircase.

The tunnels were built after World War II, designed to withstand a nuclear strike and also connect with the city’s metro network.

Many residents have no idea that under a large metal gate and modest concrete building in the heart of the capital is the old mine that served as a cover for the construction of the bunker between 1948-1961.

The visit begins with a descent of 43 meters deep by an ancient iron spiral staircase.

Next there are automatic gates and watertight doors almost half a meter wide, like on warships, designed to resist the impact of a nuclear bomb on the surface.

Guide Yegor said the complex was built “with the nuclear weapons of the 1950s in mind.”

“It would not resist an atomic bomb of the 21st century,” he added.

“This bunker would not save anyone today. If a nuclear war broke out now, I would advise them to go as far as possible from this place.”

He continued: “This is another world, even another civilization. You feel what the people of that era felt, the era of nuclear deterrence.”

The bunker, which covers an area of 1,600 square meters, is a small village that includes long corridors with cast iron pipes and huge circular tunnels up to 36 meters long which could have accommodated 10,000s of civilians.

One of the compartments in the buried fortress, which was operational between 1961-2005, was a special archive of secret documents and international treaties.

Its greatest treasure was the Molotov-Ribbentrop Pact, a secret neutrality agreement between Nazi Germany and the Soviet Union.

According to many historians, the document paved the way for Adolf Hitler to invade Poland and start the WWII.

Ministry specialists working in the subterranean complex could enter and leave without being seen by special passages that led to the metro.

There were also freight trains that could transport vital equipment and documents to and from the bunker via an alternative platform.

The shelter still has gas masks, fireproof suits, radiation measuring devices, first aid kits and other survival equipment.

It was designed to serve as a nuclear refuge for 15 days, equipped with ventilation, electricity, communication systems and individual oxygen equipment.

A map on one wall shows the entire network of Moscow’s secret bunkers, some of which are still operational.

One visitor Li Han, a Chinese student, said: “I liked it very much. It’s very interesting.

“In China, there are also bunkers, but they don’t let us see them.”