This top-secret nuclear bunker hidden in a Bosnian mountain has been converted to a modern art exhibition space.

The "dragon babies" of southeastern Europe.

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

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."

This heart-shaped island looks substantially less lovely after a recent bulldozing project.

Island wonderland for communist autocrats.

When Croatia became independent of Yugoslavia, the splintering governments left behind these concrete tunnels.

Once a state-of-the-art tuberculosis treatment spa, these ruins are now ruled by paintball players.

This Croatian fairytale castle is slowly falling apart thanks to years of neglect.

Humble beginnings for one of the world's most famous scientists.

Spend the night in 1920s Latvia in this historic recreation and movie set.

Burlesque Hospital Themed Restaurant.

Guests become prisoners on a visit to Latvian prison.

This impressively complicated radioastronomy research center was once a tool of Soviet spies.

A vast and unlikely aviation museum kept alive for over 50 years due to one man's tenacity.

A top secret Cold War bunker hidden beneath a Latvian spa facility is now open for tours.

A narrow strip of land is home to the tallest migrating dunes in Europe.

A retiree's challenge to build an outdoor wonderland out of trash.

The clients of these mysterious hand-crafted funeral cars took their last ride in style.

A toxic lake near a volcanic caldera that is home to flamingos and other life.

The inspiration for the Patagonia Clothing logo, Cerro Fitz Roy turns pink at sunrise.

Stenciled handprints and wall paintings dating back 10,000 years, some of the earliest forms of cave art.

This historic, palatial theater is now one of the world’s most beautiful bookstores.