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

This former estate of a fascist leader is now a burnt out ruin leading to a system of secret tunnels.

A centuries old castle atop a dormant volcano houses museums devoted to both women and witches.

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

Where the lovelorn find a home for their sentimental keepsakes.

Double spiral staircases are not unheard of, but they are very rare.

Austria's ultra-modern art museum looks like Cthulhu's giant alien heart.

The shell of a medieval fortress offers commanding views of the area it once protected.

Resting in the middle of an Austrian river, this sci-fi "island" lets people cross in neon style.

The world's largest historic armory was established by independent citizens to defend themselves from the wars of larger forces.

Underneath this small church are 15,000 bones, arranged by an obsessive academic.

An Austrian house of bones filled with hundreds of intricately painted skulls.

A whimsical and twisted animatronic monster tour beneath the streets of Berlin.

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

A 400-year-old mummified arm dangles from the ceiling of St. James the Greater, serving as a warning to thieves.

A medieval fresco which reminds visitors that death will come for us all.

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

Artfully arranged bones of 5,800 Austrians.

Filled with goldfish swimming in a shallow pool of sea water, this ancient crypt is more wishing well than burial site.

Bell tower juts out from a village buried under a lake.

David Sedaris called it "The greatest shop in the world."

Typewriter museum housing more than 1,500 machines preserves the history of the grandfather of computers.

Europe’s oldest natural human mummy.

According to the local folklore, the myriad colors of this lake are the result of a lovelorn wizard's blunder.