Swarms of dainty flying insects swarm into the Petaloudes Valley to get busy.

Giant marble phalluses on the sacred island of antiquity.

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

Perched on a spindly rock spire in a Greek archipelago, this lighthouse would make a perfect wizard's tower.

The hallucinogenic center of the ancient world.

A fairytale Gothic castle steeped in Nazi treasure conspiracy theories.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

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

The walls and ceiling of this Polish church are decorated with thousands of skulls, with another 21,000 skeletons just below.

The only gulag ever to exist in socialist Yugoslavia.

This stunning, out-of-the-way Croatian monument commemorates a community's uprising against occupying fascist forces.

The remains of a sunken military ship wreck visible through clear water.

Where the lovelorn find a home for their sentimental keepsakes.

A musical instrument played by the sea.

An Art Nouveau building covered in animal gargoyles and grotesques.

The deepest metro station in the world.

340-foot statue built to honour the Heroes of the Soviet Union.

A monument to Lenin has been transformed into a statue of everyone's favorite black-helmeted, fool-choking Sith Lord.

The largest catacomb system in the world.

This attraction was abandoned after the Chernobyl disaster.

This beautiful natural train tunnel is said to grant the wishes of visiting lovebirds.

The ghost town left by the worst nuclear disaster of all time is being taken over by nature and urban explorers.

Home of the future Emperors of Russia.

Moscow's other, lesser known kremlin is a fairytale-like cultural complex modeled after Old Russia.