Thousands of graves lurk below the surface of this park.

Beneath Kraków Old Town's main square lies a hologram-filled medieval market vampire graveyard wonderland.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

A baffling beast so absurd a town councilman called it "intellectual vomit in technicolor."

Cadillac where country's first big star was found dead.

A strange mishmash of ruins and abandoned structures hint at the park's many lives.

Amalfi's pre-industrial history is slowly being engulfed by the lush vegetation of the Ferriere Valley.

The remains of an attempt to carve a thriving metropolis from the forest, and once home to the first revolving door in North America.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

Train tunnel running underneath Quebec City.

Few other hotels can rival the grandeur of the Castle in the Rockies.

This Toronto garden collects stares and tchotchkes in equal measure.

A psychedelic labyrinth on the San Francisco bay.