A rococo room covered entirely in porcelain originally constructed for another royal residence.

An eerie, little-known Neapolitan museum filled with preserved human remains.

Dug as a secret royal escape route, the tunnel became a wartime bomb shelter and dumping ground for vintage cars.

These "anatomical machines" are only one of the many strange items in this Italian crypt.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

This magical-looking island is notorious for the misfortunes suffered by its owners.

The glowing blue Nymphaeum of Emperor Tiberius.

A 200-year-old collection of medical paraphernalia in a historic house.

One of the world's few mounted blue whales, its jaws are hinged open allowing visitors to descend into a lounge.

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

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

This little Greek plateau is home to thousands of rustic, white-sailed windmills.

A minotaur, a labyrinth, and a dubious restoration pull in visitors from around the world.

An extensive network of secret tunnels was created for the Nazi project "Riese."

A tribute to the first human in space.

This mushroom-shaped rock has frustrated and fascinated locals for centuries.

A statue commemorating a Polish dog who took his role as man's best friend very seriously.

This symbol of Polish heritage survived the occupation during World War II, hidden in plain sight.

A miniatures park with a model of Wolf's Lair as it looked during World War II.

The majority of the highest mountain in Poland is actually located in a different country.

A somber memorial honors the hundreds of thousands of lives lost at this labor and extermination camp.

Built to transport German U-boats through the never-completed Masurian Canal, the locks near this Polish village are now home to a rope course.

The first, and perhaps only, monument dedicated to Wikipedia.

A stone in Wolin, Poland, marks the possible location of a legendary Viking fortress.