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

One of the most photographed buildings in a city known for its Modernista architecture is an abandoned squat.

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

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

Gaze upon chocolate sculptures depicting everything from chariot races to Gaudí's famous church at this shrine to sweets.

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.

A lush indoor jungle fills this bustling Madrid transportation hub.

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

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

The only urban monument in the world designed by the great surrealist painter Salvador Dalí.

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

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

The clock that sets them all.

This tea house was a hand-built gift from Boulder's sister city in Tajikstan.

When the public was consulted about a new piece of street art, they naturally asked for an enormous metal dragon.

Cat art as far as the eye can see.

A floating cat sanctuary on an Amsterdam canal.

The mummified right fist of a 1,000-year-old saint-king sits inside an ornate golden reliquary.

A series of caves under Castle Hill that once held the prisoner Vlad Tepes, better known as Count Dracula.

Built in 1870 at the bridge that connected Buda and Pest, this spectacular incline railway was almost lost forever during World War II.

A trail of iron footwear stands as a monument to the thousands executed along this riverbank during WWII.

This massive fiberglass Gulliver turns every visitor into a Lilliputian.