Cold war icon and onetime "hole" in the iron curtain.

This water-tower-turned-high-end-apartment building was once the site of an early Nazi concentration camp.

Berlin's old airport.

Floating swimming pool within a moored vessel.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

A fountain standing as a testament to a doomed alliance.

This automated sculpture of two men peeing will spell out text messages with their micturition.

This tipsy office building in downtown Prague was originally called “Fred and Ginger.”

Countless grotesque faces stare out from this eerie Prague art wall.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.

Increasingly decayed figures stand as a powerful reminder of the human costs of Czech Communism.

A towering spire in the fortress of Kalemegdan honors the victorious armies of Serbia during their struggles against the Ottoman Empire.

A misnamed well, with a deep dark past.

Destroyed Serbian army headquarters sits half crumbled in a largely revitalized Belgrade.

A pair of connected skyscrapers form this symbolic gateway.

These historic defenses ensured the city within would survive hundreds of years of occupations, sieges, and invasions.

An ancient knight and a symbol of the city's freedom.

Gargoyle head that brings good luck.

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

Flamboyant architecture from the turn of 20th century.

3,000 market stands in five former Zeppelin hangars.

This micro-nation may be some sort of prank, but its constitution sure seems official.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.