These slanted cubic abodes are a creative if odd solution to a zoning pickle.

Birthplace of the "Cat in the Cradle" and a cluster of iconic, original windmills that let the Dutch tame the seas.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

This small town in the Netherlands has no roads but instead, miles of canals and over 100 bridges.

Colorful and chaotic stacked hotel in North Holland.

The world's first zoo for microbes collecting the horrible and wonderful things living on and around us.

The only "Egyptian" pyramid in Europe and the legendary tomb of Remus.

This ritzy Italian market is built around a statue of an unforgiven heretic who was burned for his belief in an endless universe.

18th century opera in its original splendor.

Stockholm's decidedly unique public transit system has doubled as the world's longest art gallery for decades.

Descend into the tunnels to experience the life of a coal miner.

Hiding the longest subterranean river known in the world.

Museum covers every step of the chocolate-making process, from cultivation to the finished product.

An industrial relic is now one of Europe's most staggering art spaces.

This beautifully designed star-shaped fort was the premier defense system of the late 1500s.

Böttcherstraße's bells, extolling Nordic virtues and the great conquerors of the world.

Striking occult iconography on a medieval German church.

The architect of this fanciful complex called it an "oasis for humanity and nature in a sea of rational houses."

A steam powered train that runs on city streets.

The site of a concentration camp where inmates were made to take part in one of the largest counterfeiting operations in history is now hauntingly empty.

This giant, 83-year-old ship elevator is an engineering feat to behold.

This quaint Hungarian railway system is operated exclusively by children between the ages of 10 and 14.

From Austrians to Nazis to Soviets, this historic Budapest fortress has a history as complex as the city itself.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.