Nestled in the heart of Milan is a real wunderkammer of morbid curiosities.

This overgrown mountain village has been abandoned for nearly a century.

In the fictional world of Kcymaerxthaere, celestial wonders marked a portal to a powerful route of travel at this site in Madrid, Spain.

Someone loved this song enough to carve all of its lyrics onto a tree trunk in a Berlin park.

Blitzkrieg bop your way through Berlin's Ramones Museum.

A wunderkammer of mysterious objects and stories.

The complex has been abandoned since the Croatian War of Independence, barring a stint as a set for 'Game of Thrones.'

This truly palatial work of Communist-era architecture now sits crumbling on a Croatian beach.

Once a state-of-the-art tuberculosis treatment spa, these ruins are now ruled by paintball players.

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

Where the lovelorn find a home for their sentimental keepsakes.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

The ruins of a Duke's bucolic dream, where camels once roamed alongside "Dutch" windmills and faux-Italian vineyards.

This Parisian fountain is a little bit fantasy and a little bit nightclub.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

Behind the pink curtain, Au Bonheur du Jour, an art gallery of erotic archives.

19th century pendulum and a clock restored by a rogue group of guerilla artists.

This modern labyrinth lies in the shadow of a ruined medieval castle.

This abandoned Brutalist treehouse is a hidden architectural relic.

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

This 6th-century church has the largest and best-preserved collection of Byzantine mosaics outside Constantinople.

The 1,000-year-old abbey is the birthplace of modern musical notation.

A visionary Italian architect created an impressive cluster of concrete structures for a family's private tomb.

These gutted monastery ruins still stand proudly in the middle of the Italian countryside.