Fragments of human bones are embedded in the walls of this quaint alley.

The tallest tower in Cáceres's Old Town.

An Orthodox church built by the Royal Family for the Russian community exiled to the French Riviera.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

What looks like a normal building is really a hollow facade hiding a subway vent.

This bridge was constructed from the rubble of the infamous Bastille.

The tradition of open-air secondhand and antiquarian bookselling in Paris dates back to the Renaissance.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

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

Geological storytelling.

Cliffside houses provide a spectacular view from their perch above the valley.

Two stone columns flank the grand Venice square, but there were supposed to be three.

Mountain where Jesus was first tempted by the Devil.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

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

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

Catalonia Tradition: Beating the hollow Christmas log until it defecates in your fireplace.

An unusual but excellent display created in the 1930s as propaganda against the Freemasons.

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

The facade of this 16th-century building is decorated with carvings of 300 seashells.

An array of ancient artifacts from Bronze Age Bristol and other civilizations are housed in this museum.

It houses a menagerie of wondrous taxidermy specimens from around the world, including the remains of a famous gorilla.

Banksy's image of a naked man dangling from the window of a sex health clinic.

Wall Street has a new heroine, a bronze statue of a small but fierce girl.