An open-air sewer system that was covered piece-by-piece over 300 years.

This bike path was sunk below water level for maximum wonder.

This ghost town in Belgium will lose its street art when it ceases to exist.

Hiding the longest subterranean river known in the world.

Each spring, a dreamlike carpet of bluebells overtakes the forest floor.

Nearly three decades since the fall of the Soviet Union, the hero of the USSR still stands over Belarus.

Remnants of the city's Soviet history hover over this modern fast-food outlet.

Thanks to its heroic service during WWII this Soviet castle has been turned into a monument towered over by a brutalist titan.

A breathtaking viewing platform over the Alps.

The world's most important buildings shrunk to a tiny size.

Part ski resort, part modern art space, this lodge brings giant metal spiders and bloody doors to the Austrian Alps.

American soldiers discovered Europe's best one-liner at the end of World War II.

The personal charnel house of Anton Bruckner.

The world's oldest known salt mine.

This series of underground chambers contains Europe's largest subterranean lake that is slowly drained each day.

Beautiful Austrian natural history museum with carved ceilings and row after row of ancient taxidermy.

The largest ice cave in the world is thought to be the entrance to hell according to Austrian legend.

An Austrian house of bones filled with hundreds of intricately painted skulls.

Artfully arranged bones of 5,800 Austrians.

A centuries old castle atop a dormant volcano houses museums devoted to both women and witches.

Each year melting snow turns these Austrian hiking trails into scuba zones.

Swarovski's museum/theme park is a fake diamond fantasia overlooked by a giant.

The beautiful baroque library of the Hapsburg empire.

The final resting place for the remains of 143 Habsburg royalty.