Berlin’s greatest tourist attraction is perhaps the one that’s not there – the so-called Führerbunker where Adolf Hitler spent his final days deep underground waitng for the Third Reich collapse.

A tour guide friend of mine once told me, “If I could sell tickets to that thing, I’d charge €100 a ticket and I know that hundreds of people would line up and pay that much, every day of the year.”

He’s probably right. The site where the Führerbunker stood is now a mundane parking lot in the centre of Berlin, but darker episodes of the city’s history can be explored by descending to some of the bunkers that remain open to visitors.

However, if you’re interested in getting underground you should soon – although the structures were built to survive bombing raids and nuclear blasts, strapped budgets and bureaucracy may soon claim several of the most fascinating bunkers under and outside of Berlin.

The Honecker Bunker

Bunker 5001 was East Germany’s ultimate undisclosed location. Had the Cold War turned hot, East German leader Erich Honecker and other high-ranking communist leaders would have comfortably ridden out the end of the world in this 7,500 cubic meter space.

It’s buried in the middle of a forest about 40 kilometers from Berlin. The site is filled by a tangle of decrepit buildings. Most are abandoned, some bear “Motel” signs in what was clearly a failed attempt to draw tourists after German reunification. It’s a creepy place and easy to worry that a guy wearing a hockey mask, carrying a chainsaw is going to run out of the forest and hack off one of your limbs.

My guide, Hannes Hensel, who’s part of a group called the Berlin Bunker Network, shows up and pokes around the ground for awhile until he uncovers a steel trapdoor. He opens it and beckons me inside. We won’t surface again for well over two hours.

“This was the most technologically advanced bunker of its time,” Hensel says while explaining his interest in the site. Unlike that pinnacle of the East German auto industry, the Trabant, Hensel explains that Bunker 5001 was actually superior in some respects to similar American and West German bunkers of its time.

Inside, he shows me how the East Germans built the bunker as a series of massive containers, built on giant springs and coils so that the facility could ride out the shock wave from nearby nuclear blasts. The bunker contained its own generators, water system and air filtering facilities, so that its 400 inhabitants would have had no need to enter the nuclear wasteland above for two weeks after a war. The postwar plans were a bit hazier, however.

“After two weeks, they would have gone above ground wearing radiation suits and gotten to an airplane and flown eastward to Russia,” says Hensel.

Bunker 5001 is definitely number one on the most endangered list of bunkers in the Berlin area. The site’s entrances will be sealed up with concrete sometime this fall to prevent thrill-seekers from gaining access. Tours are available on a reservation-only basis between now and October 26th. A two-hour guided tours costs €20. For €100 there’s the “Tough Guy Tour,” which promises to reveal the bunker’s “hidden secrets” – so long as you’re willing to bring along two heavy-duty flashlights.

It’s a bit of a hike to get there with public transportation – nearly two hours each way – but a quick drive if you have a car.

Berlin Underworlds

I’m in a tiny, dark room, deep underneath Berlin’s Gesundbrunnen train station. The walls and ceilings are glowing. It’s oddly calming, and no, I’m not taking any drugs.

“Don’t touch the paint, it’s toxic,” warns my tour guide, Brito Morales, an Ecuadorian with a British accent and training in Prussian history from Berlin’s Humboldt University. She leads tours for Berlin Underworlds, a non-profit group that takes over 100,000 visitors a year through buried pieces of Berlin’s past.

Morales turns off the lights to demonstrate the “psychologically soothing” qualities of a building designed to take direct hits from bombs. The luminescent paint outlines doorways, stairs and emergency exits. Despite being applied during World War II, it remains remarkably bright in darkness. While the paint may have been designed to be soothing, she says people who actually took refuge here would have had reason to panic.

“This bunker only offered the illusion of protection. To save on building costs, the Nazis only built the walls 120 centimetres thick. To be effective, the walls should have been at least two metres thick,” Morales says.

The Gesundbrunnen bunker, which connects to Berlin’s U-Bahn tunnels, was first used as an air raid shelter during the war, but in the 1970s the French, who were in charge of this zone of occupied Berlin, tried to convert it into a nuclear shelter before deciding to store some of Berlin’s emergency food supply here.

The fallout shelter was instead built one U-bahn stop away. Morales takes us there and opens an anonymous door in the station.

Inside is giant steel airlock, designed to keep out contaminated air. Those lucky enough to get a place in the bunker – there was only space for 4 percent of West Berlin’s population in the various nuclear bunkers built around the city – would have had to strip here and take a decontamination shower. Once we’re through that area, we enter an infirmary that looks like it’s ready to start accepting patients immediately. Morales claims that BVG, the company that owns Berlin’s public transit network, owns this shelter and still maintains it in case of a disaster.

But fallout of a financial, not nuclear, kind could spell the eventual end of this bunker. The German government and state of Berlin will decide in the next few years how to dispose of surplus bunker facilities such as these.

The tour around Gesundbrunnen takes nearly two hours and costs €9 for adults. Berliner Unterwelten runs a variety of tours of Berlin’s underground that each look at different period of the city’s history.

The Little Bunker of Horrors

“There are ghosts here,” Marit Friedland tells me. “When I turn out the lights, the rooms are full – and that’s without the decorations.”

Whether or not you believe in ghosts, it’s hard not to be spooked by the Gruselkabinett – which means chamber of horrors in German – that Friedland founded and operates from a former World War II air raid bunker in Berlin.

The massive, windowless, aboveground bunker sits right next to the Anhalter Bahnhof, which was one of Berlin’s most important train stations before being destroyed during the war. During the closing stages of the Battle for Berlin, as many as 12,000 refugees camped out in the bunker for days on end, seeking shelter within the building’s massive three to four metre thick walls.

Two levels of the bunker house a bizarre, grotesque fright show complete with shrieking severed heads and animatronic monsters. The Gruselkabinett’s website even has a section devoted to organizing your next birthday party there. But walk downstairs into the basement museum and the mood shifts dramatically from campy monster horror to the real horrors or war. Friedland explains that most of the exhibits were donated by “both the victims and the perpetrators.”

One room is lined with Berlin newspapers from the war, a headline screams “763 Soviet Planes Eliminated!” A display case shows off handmade cards made by children. They’re addressed to soldiers headed off to the front. One card, with a carefully drawn picture of a tank on it, reads, “Good luck on your foreign tour of duty!”

Other rooms have interviews with bunker survivors explaining what it was like to survive inside the stuffy bunker for days on end, with people sleeping on stairs and almost no access to toilets.

It’s an unnerving sight, the combination of imagined and real nightmares, but one that Friedland said is effective when it comes to educating children. “Over 30 percent of my revenue has come from Berlin school groups. The teachers love the combination,” says Friedland. “It lets them teach the kids something about the war and then afterwards, the kids can be entertained by the fright show.”

Friedland rented the abandoned building from the city of Berlin in 1995 and said she invested about €500,000 to bring electricity and water back into the building and apply for the 250 different permits required to operate the bunker. Her lease expires at the end of 2009 and Friedland said that current city officials have not responded to any of her requests to negotiate a new lease, which could mean she’d have to close.

But Friedland has pinned her hopes on the supernatural, to keep the bunker open. “If the ghosts want it to continue, they’ll find a way to make it happen,” she says.

The Gruselkabinett is centrally located and easily accessible by the S-Bahn and U-Bahn and is open daily. Adult admission costs €8.50.

Additional bunker tours available in Berlin:

The Story of Berlin – Another nuclear bunker that also houses an exhibit about the 800 year history of Berlin.

Sammlung Boros – An aboveground World War II air raid bunker that now houses an exclusive collection of modern art. Weekend tours available with advance registration.

For more information see the external links below.