A mud brick kasbah with a history of lavishness and traitorship.

A fortified city, home to a remaining population of five families

One of the most spectacular canyons in the world.

You can still walk across this beautiful medieval bridge in Andorra.

One of Antoni Gaudí's most classic buildings is well-known for its "dragon-back" design.

An ancient quarry rediscovered by a dog and claimed by biblical kings, a German cult, and the Freemasons.

Slum Settlement Filled With Mountains of Garbage.

A 1970s resort city now stands abandoned, caught in the middle of a divided island.

Believed to be the longest railway bench in the world.

WWII artifacts, including the building itself.

England's largest white horse isn't even white.

Astonishing rock formations dot the Brimham Moor landscape.

A long, winding trek rewards you with a gorge so captivating it inspired a painting in the Tate.

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

The little-known second castle that William the Conqueror built in York.

One of the shortest streets in York has an especially odd name.

Follow the original medieval paths that wind through this intriguing section of the city.

Explore Hull's historic Old Town by following the sea creatures scattered throughout its charmingly cobbled streets.

The phone booths in this English town have distinctly milky hues.

This memorial museum chronicles the apocalyptic destruction of the First World War.

This enormous secondhand bookstore inside a Victorian train station sparked the "Keep Calm and Carry On" craze.

This iconic 1,000-year-old medieval castle is a favorite of the film industry, most notably as the location for Hogwarts in Harry Potter.

The sign at the garden gate reads: "These Plants Can Kill."

The raised stones in the middle of this road through Culross are relics of a 17th-century class divide.