In Berlin, a subterranean Nazi-era world

• A local, slice-of-life story from a Monitor correspondent.

Beneath Berlin’s streets lies a netherworld of underground lakes; canal systems with vaulted ceilings; eerie, Nazi-era murals; and the remains of a Messerschmitt factory. These tunnels, built by Hitler’s architect, Albert Speer, were intended to run down the north-south axis of Hitler’s new vision for the city, to be called “Germania."

Today, a club called Berliner Unterwelten (Berlin Underworlds) is devoted to mapping and exploring Berlin’s subterranean topography. It leads expeditions into the World War II bunkers and tunnels. Dietmar Arnold, a freelance architect and a member of Berlin Underworlds, believes that the project has the potential to become an offbeat tourist attraction, like the catacombs of Paris, the sewers of Vienna, and the cisterns of Istanbul, Turkey.

“Berlin doesn’t have many historical remnants from the Nazi period,” he says. “Only Tempelhof Airport and a couple of other buildings give one an insight into the Nazi mind.”

According to Mr. Arnold, central Berlin is honeycombed with bunkers. The Führerbunker, where Hitler spent his last days, was destroyed in 1996, but according to Arnold, some 600 other bunker complexes still exist in Berlin, though most are flooded and inaccessible.

“Maybe people are ashamed of our history,” says Arnold. “But we must reflect on our history and make sure that this kind of thing doesn’t come up again.”