A true Valhalla for cactus and succulent lovers.

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

A market built atop boats is one of the few floating holiday markets in Europe.

Europe's official "zero-level," the equator of elevation.

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

This Netherlands museum holds a gloriously mechanical collection of ornate musical automata.

A former plague hospital turned medical museum.

The former home of a mad diplomat is said to still be marked in bloody, arcane scrawls.

A rare tour of an aristocrat's private home reveals valuable 17th-century paintings from artists like Rembrandt.

Invisible bridge parts the waters, invoking biblical images and preserving the ominous feel of an ancient moat.

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.

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

This massive mural by famed pop-artist Keith Haring was hidden for almost 30 years until its 2018 rediscovery.

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

Oldest Museum of the Netherlands is a true cabinet of curiosities.

A poignant museum dedicated to the history of the Dutch resistance against Nazi occupation

Tucked in the back of a flower shop, its collection details the fascinating history of the Netherlands's iconic symbol.

Amsterdam's former hotspot for public executions and dissections.

Hidden within a Netherlands crater is a stone bed that lets those who lie in it see the sky as a curved surface.

A unique collection of gilded age mechanical pianos.

A public urinal so pretty, it was declared a national monument.

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

An overgrown and largely forgotten cemetery lies hidden within the outskirts of Amsterdam.