Medicinal spa created with the discharge from a geothermal energy plant.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings 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.

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

This unreal Portuguese palace looks as though it's made from a pile of different castles.

A Black Forest cuckoo clock theme park features one timepiece big enough to walk inside.

The narrowest street in the world is in danger of closing up entirely.

This cheeky statue of a man defecating gold coins graces the facade of a medieval guildhall.

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

The castle where Martin Luther secretly translated the New Testament from Greek to German while in hiding.

This historic toy museum brings a little whimsy to a city not usually remembered for such things.

This historic funicular system combines the old with the new while offering delightful views over the surrounding valley.

Dress up like a miner and take a slide into the disco-lit depths of this once foundational salt mine.

A castle from the Holy Roman Empire that hosts traveling youth... in its stables.

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

A small but immensely extravagant palace built by the "Night King."

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

This collection of over 50 murals celebrates Brussels' rich history as the self-proclaimed home of the "comic strip."

An expansive complex of subterranean tunnels is all that remains of one of Europe's most formidable medieval fortresses.

A surviving remnant of the thick ice mass that once mantled most of Western Canada's mountains.

Few other hotels can rival the grandeur of the Castle in the Rockies.

Fossils, railroads, and waterfalls!

This expansive bridge in the Canadian wilderness was originally just built for friends.