Once a resting spot for King Fernando VII.

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

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

A beautiful little castle with a rich history now home to the Archives of the Spanish Air Force.

This grape-growing paradise is one of the oldest vineyards in North America.

A window into a long-lost world, these colorful tiles advertise a long-defunct range of purgative teas, harmless smokables, and diarrhea cures.

One of Madrid's oldest trees, with a long and colorful history, resides in El Retiro Park.

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

In this 400-year-old hotel in Madrid, you'll find a comb in every room, an old clock, and maybe a ghost.

The remains of this misplaced church were moved here stone by stone.

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

Notorious artist squat renovated into legal studios.

This frog-themed restaurant was frequented by Picasso, Saint-Exupéry, and more.

A 16th-century fountain marks the site of a lost medieval cemetery once filled with mass graves.

An "inside out" building in the historical center of Paris, featuring Europe’s largest modern art museum.

This iconic Parisian bookstore doubles as the "Tumbleweed Hotel" for traveling writers.

One of Jeff Koons’s largest sculptures and his first commemorative work.

This bridge was constructed from the rubble of the infamous Bastille.

The spiral staircase hidden inside this giant Parisian column was likely built for Catherine de Medici's astrologer.

One of Monterrey's oldest buildings is perched atop a hill boasting impressive views of the city.

A mysterious, ancient collection of pre-Hispanic petroglyphs hidden deep in the Mexican desert.

This ”skyspace,” which bears a resemblance to a spacecraft, is designed to disappear in the presence of light.

A mountaintop shrine named for the road to heaven.

After it was missing for a decade, this 40-foot statue of Our Lady of Guadalupe was found and returned to a place of honor—with a little help from a tropical storm.