Abandoned Nazi train station turned underground astroparticle laboratory.

An architect transformed this abandoned cement factory into his castle-like workshop.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

A 14th-century fortified keep showcases the masterpieces of an ingenious 20th-century clockmaker.

Rare wooden escalators lead deep down into an otherwise staggeringly monotonous tiled tunnel.

A slice of central Asia in the middle of Berlin.

This medieval castle overlooking the Elzbach river looks just like it did hundreds of years ago.

The beautiful baroque library of the Hapsburg empire.

The final resting place for the remains of 143 Habsburg royalty.

This fantastical icy castle is built anew every winter.

The world of the ancient Celtic civilization explained through a bewitching 11 acre garden.

Skeletons dressed in extravagant 18th century royal costumes cavort in the aisles of this German basilica.

A narrow passage next to a cafe leads to a courtyard exploding with murals, tags, and paste-ups.

This futuristic German spa allows visitors to float in a pool of salt water while zoning out to underwater techno.

An eerie, derelict amusement park in Berlin.

An apparition of Virgin Mary in Herzegovina.

A field filled with carved medieval tombstones called stećak.

A wellspring of natural Viagra found in Bosnia.

The sad remains of a monument to martial arts legend and movie star Bruce Lee—in the middle of Balkans.

A forgotten and crumbling Yugoslav monument to the victims of fascism.

This historic cemetery was inaccessible for several years due to dozens of land mines.

This museum preserves the hand-dug tunnel that kept Sarajevo afloat during the Serbian siege.

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

Where the lovelorn find a home for their sentimental keepsakes.