A flamboyant five-story building in Bulgaria resembles a crawling snail.

The ceiling of Prohodna Cave in northern Bulgaria affords a peek at the sky via two deity-sized-eye-shaped holes.

The ancient Greek Titan guards this massive dam holding a lightning bolt to symbolize electricity.

The bust of Romania’s most notorious ruler, Vlad Dracula aka "Vlad the Impaler," keeps watch over the ruins of his medieval court.

This once-derelict building is now one of the most beautiful bookstores in the world.

Once an opulent Art Nouveau hotspot, the Constanța Casino is one of Romania's most beautiful abandoned buildings.

On Gellért Hill, this statue depicts the tragic tale of lovers divided by the Danube.

Launched by Napoleon's soldiers more than 200 years ago, a cannonball remains embedded in the tower wall.

A large concrete replica of a 12th-century figurine.

Dedicated to the god Dionysus, this theatre was used for both musical and theatrical performances.

A century-old prison in the heart of Vilnius is now a lively bar, dance club, and artist residency.

Once the tallest building in Chisinau, this unique tower is a relic of Soviet architecture.

This historic black and white monastery is one of Bulgaria's architectural jewels.

Space-age monument to an early 20th-century uprising.

This medieval castle was reconstructed by Carlo Scarpa.

This tiny Bulgarian town offers a stunning location in the mountains and a storied history.

The temple that withstood the Nazis.

Not far from the more famous House of Juliet, visitors will find the supposed residence of her lover.

This abandoned airplane hanger is said to have once been a top secret launch facility.

A bridge destroyed three times: once as a ruse, then in an actual attack, and finally for the movies.

This brutalist monument is inscribed with 9921 names of Yugoslav partisans who perished during WWII.

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

These warring psychedelic crags commemorate an unsuccessful military operation.

This cluster of little wooden huts once ground local farmers’ wheat into flour during the days of the Austro-Hungarian Empire.