Bizarrely-painted church designed by a controversial artist.

The housing complex served as an anti-fascist fortress during the Austrian Civil War.

The world's largest historic armory was established by independent citizens to defend themselves from the wars of larger forces.

Austria's ultra-modern art museum looks like Cthulhu's giant alien heart.

This series of Baroque passageways in Vienna's cultural center mix old architecture with modern art.

Resting in the middle of an Austrian river, this sci-fi "island" lets people cross in neon style.

Double spiral staircases are not unheard of, but they are very rare.

Op-art architecture designed for happiness.

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 final resting place for the remains of 143 Habsburg royalty.

The crypt of the imposing Stephensdom holds royal intestines and thousands of skeletons.

The 20-mile causeway that separates the Netherlands from the sea.

Amsterdam's former hotspot for public executions and dissections.

Rich with fauna and flora, nature-lovers can walk across the sea at this UNESCO World Heritage spot.

A miniature city, once ruled by the Queen of the Netherlands.

A little sculpture with a large wardrobe.

Climb inside an iron crystal magnified 165 billion times its normal size.

18th century opera in its original splendor.

This striking royal residence is the largest Renaissance-style castle in Scandinavia.

A distinctive former power plant turned university lecture hall looks like it could make you breakfast.

The skeletal frame of a decommissioned gas-pumping station offers breathtaking views of greater Berlin.

This historic toy museum brings a little whimsy to a city not usually remembered for such things.

Take a walk in a recreation of ancient Rome.