Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

Of the many chalices in the running for the Holy Grail, this one in Valencia Cathedral sure looks the part.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.

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

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.

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

Two towns are linked by an engineering marvel masquerading as a boring suspension bridge.

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

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.

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.

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

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

The world's oldest bookshop still in operation.

Legacy of the earthquake that nearly wiped Lisbon off the face of the Earth.

The body of at least one victim of a construction accident was left behind in the collapsed pylon, buried under tons of concrete.

The largest bell in the world has been swinging high above a Cologne cathedral for almost a century.

Thousands of tourists and residents in Cologne affix "love padlocks" on the Hohenzollernbrücke Bridge to symbolize their affections.

Before serving as James Bond's Casino Royale, this Victorian-era spa catered to the world's elite.

An enormous and lavish Gothic church in Czechia.

A museum of alchemy and a basement laboratory all housed in an ancient building in a Gothic tower.