Ghost stories surrounded this “castle,” the only structure from a huge mansion that was never built.

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

Construction of Barcelona’s iconic (but controversial) church was finally completed in 2026—a century after the death of its architect.

Meant to resemble a massive tree, the building is the best example of Spanish organicist architecture in Madrid.

The only urban monument in the world designed by the great surrealist painter Salvador Dalí.

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

An ancient Egyptian temple in the middle of Madrid, Spain.

Marvel at this turn-of-the-century masterpiece that has been turned into a rather stately supermarket.

This retired stagecoach tavern is the oldest building in Cleveland.

The only depiction of Abraham Lincoln holding a weapon, and the names of all 9,000 Cuyahoga veterans of the Civil War.

This amazing example of Valencian Art Nouveau looks more like a cathedral than a public market.

A cemetery in Barcelona's Poblenou district is home to this touching funerary statue, which depicts death in the form of a winged skeleton.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

The iconic boulevard is the perfect place to catch sight of a bicycling skeleton, a levitating Satan, or a chef with his head stuck in a pizza.

One of Antoni Gaudí’s earliest buildings, built between 1886 and 1890 for the industrialist Eusebi Güell.

Down this yellow brick road, visitors are treated to toadstool houses and massive mushroom sculptures.

This magnificent market stands as a poignant symbol of the suffering caused by the Spanish Civil War.

This architectural oddity is an oasis of green on the outskirts of Valencia.

A dazzling display of lights and crystals.

Funded by John D. Rockefeller, this is one of the earliest, and most beautiful, shopping arcades in America.

A glimpse at Walt Disney's vision for a "community of tomorrow," in miniature.

If you don't look closely, you might mistake this sculpture for just another passenger waiting at the airport.

A tiny piece of the Moon is embedded in this stained glass masterpiece.

The sci-fi villain is a little-known inhabitant of the U.S. capital's largest cathedral.