The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

These medieval skyscrapers dominate the skyline of this small Tuscan town.

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

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

Thanks to an acoustic anomaly, this unassuming stone bench has heard one hundred years of secrets.

The effect of this ancient form of image projection situated atop an 11th century Moorish palace is thrilling.

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

This remarkable museum sprung from one of the most important prehistoric archaeological sites in the world.

The world's first electric battery-powered submarine.

An impressive display of ships and artifacts from the ancient Mediterranean maritime trade.

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

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.

Geological storytelling.

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

This 19th-century fountain's namesake animal isn't what you think it is.

Giant topiary dog once played a role in a terrorist bomb plot.

A towering monument in Spain has proven to be more labor-intensive than initially planned.

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

Over two centuries old and counting, Madrid's massive botanical garden contains one of Europe's only desert environments.

Commonly acknowledged as the only public monument to the Devil himself.

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.