A 'living museum' in Leiden, the oldest of its kind in the Netherlands.

The ruins of this Dutch castle sit atop a labyrinth of once-secret tunnels and passageways, dating back over 900 years.

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

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

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

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.

Colorful and chaotic stacked hotel in North Holland.

A beautiful maze marks where three countries meet.

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

This easily overlooked memorial immortalizes the scars from the 1956 Hungarian Revolution.

A statue in Budapest's Liberty Square honors the former U.S. president's efforts to end the Cold War.

Uh, pardon me, ma'am, but I couldn't help noticing that there's a Columbo statue in the middle of Budapest.

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

One of Amsterdam's narrowest houses is located right across the canal from its widest.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

Amsterdam's former hotspot for public executions and dissections.

The world's oldest Jewish library was founded by Sephardic Jews in 17th century Amsterdam.

The largest collection of handbags in the world, the oldest of which were used to carry Bibles, primarily by men.

A beautifully eclectic mix of architectural styles.

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

An engineering masterpiece, or “Scheme of Madness?”

Alien rock formations grown from the sands of an Australian national park.

Follow the original medieval paths that wind through this intriguing section of the city.

This one has sailed five times as far as Sir Francis Drake's famous ship.