A pair of connected skyscrapers form this symbolic gateway.

There's a mini version of Iguazu Falls hidden in the Balkans, and it's got a rope swing.

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

A number of craters left by fatal mortar strikes have been filled with red resin to remember those lost during the Siege of Sarajevo.

This ironic war memorial thumbs its nose at a campaign of inedible humanitarian aid food products.

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

This scale model of our solar system hid in plain sight for years before a physics team sought out all the planets.

The yawning maw of this pagan visage is said to bite off the hands of liars.

A war-torn Olympic relic is being overtaken by graffiti and nature.

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

This was once the center of the Birdman cult, and is now a World Heritage Site.

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

3,000 market stands in five former Zeppelin hangars.

A futuristic, brutalist masterpiece that is also strangely prison-like.

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

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

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

A tiny church on a man-made island in the Adriatic.

A chain of 16 wondrous lakes formed as a result of the gradual dissolution of soluble layers of bedrock.

A Surreal flight of architectural fancy in Vietnam's Central Highlands.

Berlin's old airport.

A musical instrument played by the sea.

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