A black cat protests the City Guild in Riga's Old Town.

Gigantic mosaic sculptures of the figures on Tarot cards fill this colorful Tuscan garden.

This quaint Italian town keeps losing ground as the sides of its plateau slowly erode.

Also known as the Square Colosseum, this building is a prime example of fascist-era rationalist architecture.

The studio built by fascists in the hopes of "reviving the film industry" with the occasional propaganda film opportunity thrown in.

The "Greatest Sewer" of ancient Rome is one of the oldest sewer systems in the world, and is still in use.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

2300-year-old Roman road connecting the empire.

The glowing blue Nymphaeum of Emperor Tiberius.

This hidden Art Nouveau courtyard is an opulent feast for the eyes.

Geothermal waterfalls in Tuscany.

An Italian crevasse filled with abandoned buildings gives visitors a look at the world without humans.

The ghost town where the villagers refuse to leave.

Monasteries on rock pillars, once accessible only by frayed ropes.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

This dizzying tower was built to better broadcast the 1980 Moscow Olympics.

Disused seaplane hangar gets a second life as the jaw-dropping home of Estonia's museum of maritime history.

Estonia's largest creative city is a vibrant bohemian hub located within a former industrial complex.

An empty relic of the Moscow Olympics crumbles away in Estonia's capital.

A musical instrument played by the sea.

This abandoned Slovenian military barracks has become a punky-political art squat.

A whimsical bridge adorned with decorative dragons.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.