This simple roadside art installation ended up sparking a folk art movement and a controversy of international proportions.

Enigmatic bug-like sculptures mystify drivers along a Swedish highway.

The silly symbol for an underground protest group is now scattered around the city.

Those who own or stay at this 500-year-old, allegedly cursed house often meet terrible fates.

The only museum with its curator—and her pets—buried inside.

A sinister pyramid in the Frari contains the heart of the famous neoclassical sculptor.

A new sculpture calls attention to climate change in the centuries-old city it threatens.

The former Nazi concentration camp stands as a museum to remember this dark chapter in European history.

This macabre masterpiece of a mural is one of Francisco Goya's "Black Paintings."

The ruins of an ancient stadium that hosted gripping chariot and horse races.

A display of torture devices used in the Spanish Inquisition and other scourges of medieval Europe.

These magnificent city walls rise from the barren sun-baked Spanish plains like something straight out of a fairytale.

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.

The 2,000-year-old Roman columns are hidden within Barcelona's Gothic Quarter.

Possibly the oldest church in Barcelona, this basilica has its pagan and Christian mythologies all mixed up.

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.

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

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

The largest Art Nouveau complex in the world is a Barcelona hospital with a 600-year-long history.

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

Stunning Roman aqueduct used for 1900 years and still standing.

Long tunnels run under the ancient chariot racing circuit to the tower.

This massive monument towers over the city as a constant reminder of the lives lost during Algeria's hard-won war for independence.