A beautiful maze marks where three countries meet.

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

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

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

This disused VLF radio station is no longer in service but the surrounding town still bears its name.

Go inside a revolutionary, cage-less zoo where 70 species of monkeys roam free alongside their human visitors.

The tallest waterfall in the Netherlands is a lovely, stepped feature that is only 50 feet tall.

The hidden lair of an alchemist rediscovered in a 2002 flood.

The birthplace of an eccentric alchemist and possible inspiration for the fictional reanimator of monsters.

The largest ice cave in the world is thought to be the entrance to hell according to Austrian legend.

In this brilliant blue spring in Germany, legend has it that a sad mermaid learned to finally laugh.

This ancient ruined monastery has been destroyed by fire so many times that it seems like God hates it.

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

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

The oldest stone house in Paris was built by its most famous alchemist.

Abandoned railway line circling the city of Paris.

France's most famous cemetery, with some of its most curious tombs.

The verdant mossy ruins of a Franciscan monastery lie in the remote Sintra hills awaiting exploration.

A unique seaside cave where Aleister Crowley faked his own death.

In Portugal, a secluded stretch of untouched natural beauty hides at the bottom of a steep hill.

One Portuguese poet described this cape, the westernmost point in mainland Europe, as "where the land ends and the sea begins."

An ancient and majestic fortress that played an integral role in Portugal's road to independence.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

The world's oldest bookshop still in operation.