After coming to Prague more than a decade ago, US journalist Christian Falvey has become fascinated with these labyrinths.

“This is the only place where you can see such interesting and terrifying pictures as these,” he says pointing at the evacuation schemes on the wall. “They show how to prepare your house for a nuclear attack.”

Falvey walked RT through the endless tunnels showing off what may be thought of by some as “ancient technology”.

“This is the diesel generator that would supply the whole bunker with electricity, made by Skoda,” he said. “And here’s the filter to clean all sorts of noxious gases, toxic gases. All these devices are in perfect working order.”

Cold War replaced with cold drinks

Porukazka Bunker has become one of Prague's trendiest underground venues.

Jarda Svec, punk musician and club owner, said the bunker is only a year older than him. “You feel the weight of totalitarianism on you,” he adds. “But ours is a venue for free-spirits. We've never made any money out of it!”

Regardless of whatever part these tunnels have to play in Prague's post-Communist rebirth as an Eastern European party capital, their original purpose is never forgotten.

“I just hope there is no war,” said Rostislav Guth, Chief of Prague Undergound. “But if there is, these tunnels will be ready to take people for three days. We are always prepared.”