These quaint French houses dangle precariously over a precipice.

This stunning natural double arch, the largest in the Alps, went undiscovered until 2005.

The music is over at the Ballhaus Riviera Ballroom, but the ballroom remains in haunting disrepair.

The site of good faith and good nature in the fictional world of Kcymaerxthaere.

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.

An abandoned swimming pool decays on the outskirts of Berlin.

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

Berlin's old airport.

Floating swimming pool within a moored vessel.

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

A tree-like building perches on its trunk in the Steglitz neighborhood of Berlin.

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

A slice of central Asia in the middle of Berlin.

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

This classic restaurant features a gorgeous mirror-clad room.

Art and a pun, all in one.

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

A hands-off space for graffiti artists to hone and display their skills.

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

A tongue-in-cheek arcade where the games are based on everyday life.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

This collection of illusory paraphernalia has been culled from the history of London's premier magician's club.

A kaleidoscopic warehouse-maze of handmade neon signs.

The 700-year-old fortress was the site of Count Orlok's castle in "Nosferatu."