The world's largest prehistoric copper mine had 30,000 animal bones scattered throughout the maze of passageways.

This 14th century tower house was once the home of Irish poet W.B. Yeats.

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

Hidden in an Italian forest is a completely homemade amusement park that has taken a lifetime to create.

Crumbling ruins of the thermal baths that once attracted royals and aristocrats from throughout Europe.

The mystery of the Putim Ossuary involves a tricorn hat.

This community on a small Venetian island has taken to painting their houses in bright neon hues.

Terrifically morbid cemetary and site of famous Paracelsus' grave.

Trick water gardens from 1619 featuring a 200 piece mechanical theater powered by water.

In the town of Třeboň, carp is king.

The deepest sinkhole in Central Europe comes with a grisly tale and an unusual nickname: “The Stepmother Abyss.”

Before building her own tombstone, an untrained artist created a concrete menagerie in her garden.

Mummified monks and the accidentally interred, in a 17th-century crypt.

This network of conjoined cellars was riddled with traps and supposedly allowed the townspeople to pretend their homes were deserted.

An extraordinary museum devoted to the pop art legend created by Slovak artists.

A muddy alien landscape that is home to rare species of exotic plants.

A perfectly preserved hill village where the buildings are painted like white lace.

Too much gossip or just missing curfew could land you in here for a couple of days.

An ancient Thracian city where fire rituals were practiced on the largest cult altar in Southeast Europe.

Each year melting snow turns these Austrian hiking trails into scuba zones.

One of the best collections of wax anatomical models in the world.

The former private quarters and office of Dr. Sigmund Freud now hosts a museum housing the works of the founding father of psychoanalysis.

A spherical "micro-nation" in the heart of Vienna.

This one-time health resort was used by aristocrats around the world.