France's most famous cemetery, with some of its most curious tombs.

The vast, legendary catacombs hold secrets much stranger than stacked bones.

Metro station with a claim to rock n' roll fame.

Cold war icon and onetime "hole" in the iron curtain.

These former Nazi anti-aircraft towers offer a singular view of the north of Berlin in the summer, and a sanctuary for bats in winter.

The walls of Germany's Parliament still show the scars of the Red Army takeover in World War II.

This conical hill was built as a testing ground for an engineer known as the Glider King.

A restaurant and observation deck built in a unique broadcasting antenna.

Berlin's old airport.

A 12th-century fortress containing some of Berlin's oldest buildings.

The site of the famous Nazi book burning campaign of 1933 remembers its "Night of Shame".

This World War II bunker now survives as a documentation of the Nazi regime and war crimes.

An abandoned NSA listening post on Berlin's "Devil's Mountain."

A collection of abandoned typographic signs from Berlin and beyond.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

Art and a pun, all in one.

The largest free-standing aquarium in the world resides in a hotel lobby in Berlin.

A state-of-the-art medical facility from the Imperial era is now a derelict ruin.

The most visited, and possibly most controversial, museum in Germany.

Started as a kitchen garden, now the second largest botanical garden in the world.

An eerie, derelict amusement park in Berlin.

This sculpture by artist Fritz Keonig survived the 9/11 attacks and now stands as a monument to the victims.

The remnants of two World's Fairs are here, complete with a 12-story globe, a mini-Manhattan, and a UFO-shaped pavilion.

Love, knishes, and best wishes from this legendary Lower East Side bakery.