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

The best-preserved Roman small town in North Africa.

This Polish cave has housed a dragon, a brothel, and an enduring legend.

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

Harry Potter once visited this massive limestone cliff, which was carved by an ancient glacial river.

Cliffs full of fossils at the portal to England's Jurassic Coast.

The old observatory in Copenhagen has a spiral corridor used as a racetrack.

A little sculpture with a large wardrobe.

Ancient Egyptian wigs, South American feather headdresses, a bounty of anthropological artifacts in Oxford.

Museum celebrating the history of computers, especially their role in codebreaking.

Three floors of musical instruments coming from all corners of the world and hundreds of years of musical history.

The world's oldest model village.

A formerly glacier-tipped volcano that inspired none other than Jules Verne.

Pop culture has helped to keep this iconic British building from being destroyed.

Stunning Roman aqueduct used for 1900 years and still standing.

A building so large that it has its own weather.

This abandoned-looking amusement park is frighteningly open for business.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.

A complex of six forts embedded in the Rajasthan hills.

Home to the most complete dodo remains known - one head, and one foot.

An extraordinary "City of Caves" carved from solid stone.

This tumultuous Icelandic lava field looks so alien European researchers want to use it as a stand-in for Mars.

Twisted girders are all that remain of an Icelandic bridge that was wiped out by a combination of volcanic heat and glacial floods.

This beautiful, historic church looks like something out of a simpler past.