Eighty million natural history specimens call this gargantuan museum home.

The anatomical-pathological collection of a man who changed surgery.

One of the few remaining ancient aqueducts described by Frontinus as 'the most solemn testimony of the Empire.'

The Cathedral of Salamanca has a number of unusual carvings but none so surprising as a modern astronaut.

12th-century holy complex shares land with a natural park full of heavenly waterfalls and raptors.

Of course Salvador Dalí lived in a castle...

Construction of Barcelona's iconic (but controversial) church is expected to be completed in 2026—a century after the death of its architect.

The "Little Ones," show Portugal in full miniature splendor.

Giant topiary dog once played a role in a terrorist bomb plot.

The curios of pharmacist and collector Henry Wellcome.

The only university zoological museum in London houses extinct animals, bizarre natural history specimens, and a Micrarium of microscopic creatures.

In this cobwebbed old operating theater, you can practically hear the screams of the unanesthetized patients.

One part local history, 99 parts gruesome haunted house.

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

An 18th century wonder of the world, lost in WWII, re-created at the Catherine Palace.

A cathedral resurrected from the ashes of one of Europe's greatest urban fires.

An abstract monument to a symphonic composer.

A subterranean house of worship carved right out of the bedrock.

Natural stone arches form a walkable "cathedral" at low tide, then disappear entirely when the water returns.

Madrid's romantically ornate crystal palace has been offering shelter to plants and art for over a century.

The oldest Roman lighthouse still in use.

The remains of an encyclopedic sculpture garden later used as an internment camp.

Remarkably intact Roman stone fortifications have encircled this Spanish city for centuries.

A 12th century church completely covered in shells.