This centuries-old gothic monster has been converted into a sprawling, glossy bookstore.

The Bloemen Route, or “Flower Route”, stretches 25 miles through prime Dutch tulip country as a result of “tulip mania,” the world’s first economic bubble.

Unsurprisingly, Holland is home to one of the most magnificent flower gardens in the world.

Colorful and chaotic stacked hotel in North Holland.

This 22-floor tower's Skydeck offers panoramic views of Amsterdam.

This German museum devoted to the simple wonders of salt is actually built over an old saltworks.

A fascinating little museum dedicated to the thousands of chemical substances concealed in our food.

A striking 12th-century-style castle built on the edge of a cliff.

A stairway to heaven, or to nowhere at all.

Berlin's old airport.

It's always summer at the beach inside this former airship hangar.

No need to strap in for a "ride" on this walkable roller coaster.

A German apartment building hosting as many trees as human occupants.

What was once a bustling mining installation is now a bustling hub of contemporary art.

A garden of flying flowers.

Lavish royal estate punctuated with heated greenhouses.

Museum in a swimming pool where the water still flows.

This annual Belgian water race attracts bathtub captains from all over the world.

Theme park featuring miniature replicas of European monuments.

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

Peek through a transparent pyramid and drink in the mountain made of books.

Giant wind turbine with observation deck at the very top.

This peculiar museum offers hands-on interaction with seemingly intangible principles of mathematics.

1898 German railroad depot museum with working engines, steam train excursions, and hands-on displays.