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.

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

Remarkably intact Roman stone fortifications have encircled this Spanish city for centuries.

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

A medieval village holds a very modern hotel.

Devastated landscape used for hundreds of years by the Romans as their primary mining site.

The most elaborate of 12 medieval arched doorways to the old city of Burgos.

Elaborately carved to showcase the glorious wealth that the age of exploration brought to the Portuguese empire.

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

This underground church is topped with a 500-foot cross that is seen by many as a beacon of fascist hubris.

This influential Renaissance-era library was once the haunt of kings and monks.

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

This sweet-toothed bear searching for snacks has been a symbol of Madrid for decades.

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

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

A lush indoor jungle fills this bustling Madrid transportation hub.

An awe-inspiring mosque in Morocco with one of the tallest minarets in the world.

Considered the birthplace of the Copper Age and Bronze Age, the river is tinted red from 5,000 years of mining.

The Roman city was the birthplace of various emperors and is home to one of the empire's most impressive architectural feats.

The world's largest wooden structure.

A 16th-century Andalusian palace.

The final resting place of the great navigator, or maybe his brother.

Rare karst landscape eroded from a flat seabed.