This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

This off-beat, quirky communism-themed bar isn't afraid to poke fun at its history.

Uh, pardon me, ma'am, but I couldn't help noticing that there's a Columbo statue in the middle of Budapest.

Museum dedicated to the terror regimes of Hungary.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

A random tree outside a Budapest hotel has become a DIY shrine to the late singer.

A statue in Budapest's Liberty Square honors the former U.S. president's efforts to end the Cold War.

This easily overlooked memorial immortalizes the scars from the 1956 Hungarian Revolution.

The largest mosque in Germany.

A cemetery for Slovenian notables also serves as a popular recreation space.

The "dragon babies" of southeastern Europe.

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

A miniature train-ride through Slovenia's largest cave system.

This massive subterranean fissure is known as the "underground Grand Canyon."

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

An otherworldly alpine pasture with its own unique microculture that recalls Middle Earth.

This one-time health resort was used by aristocrats around the world.

A trough of 700 strange bronze faces runs through a narrow alley in Ljubljana's old town.

Martin Bricelj Baraga's monolithic sculpture measures the blueness of the sky, and changes color to match it.

This small Slovenian town has become a magnet for microbreweries.

A kindergarten shaped like a cat with a tail that's a slide.

A German town is growing a building out of trees.

Built to test magnetically levitated elevators, the tower also boasts Germany's highest visitor platform.

The great Danube river starts here.