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

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

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

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

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

A wunderkammer of gold and silver reliquaries and ancient saintly bones.

Gargoyle head that brings good luck.

The complex has been abandoned since the Croatian War of Independence, barring a stint as a set for 'Game of Thrones.'

The unusual sculptures are believed to be powerful political symbols.

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

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

A Serbian church lit by chandeliers made of weapons.

An apparition of Virgin Mary in Herzegovina.

A former bank seized as a sniper vantage point during the Bosnian War is now a secret graffiti art gallery.

The sad remains of a monument to martial arts legend and movie star Bruce Lee—in the middle of Balkans.

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

Bridge that died in war and was resurected.

A curious cave church carved into the face of a cliff.

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

Bronzes and busts that once stood in the city's main squares are now relegated to a small hidden courtyard.

Gigantic water vessel, permanently grounded in Southern Albania.

What happens when you cross a mayor and a painter?

This ominous Albanian fortress houses tanks and downed planes as a reminder of their victories over Western imperialism.

Hundreds of thousands of concrete bunkers crowd Albania long after the fall of Communism.