A stone slab in Madrid marks the point from which the distances of Spain's national roads are measured.

This funky former tobacco factory is one of the most striking examples of Madrid's cultural diversity.

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

An ancient Roman theatre restored to its former glory in the Spanish city of Cartegena.

A huge cathedral single-handedly constructed by one eccentric monk.

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

A lush indoor jungle fills this bustling Madrid transportation hub.

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

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

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

This whimsical winery by Antoni Gaudí looks ripped from the pages of a fairytale.

Abandoned for decades, trains still pass through the now-restored remains of one of Madrid's first metro stations.

Bacteria and algae give the salty water its bubblegum hue.

The oldest restaurant in the world is this old-world Spanish eatery, still known for its suckling pig.

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

Hundreds of stone stairs and a winding medieval bridge connect this haunting Spanish island to the mainland.

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

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

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

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