Dedicated to a young woman who broke gender barriers at the University of Madrid.

This postmodern apartment block was designed to be a vertical neighborhood.

Among the oldest structures in Madrid, these Moorish walls once guarded the medieval city of Mayrit.

The entrance to this sinisterly named tunnel hides behind a Tim Hortons.

A 2,000-year-old Adena burial mound located along a busy street in Columbus, Ohio.

These sub-farmland caves are home to a majestic stalactite known as the "Crystal King."

This former tuberculosis treatment facility now stands at the center of a public park.

The concrete shell of an industry giant remains as a playground for graffiti artists, auto scrappers, and paintball warriors.

Enormous small-business mecca in the Midwest, serving dozens of artists.

Hamissi Mamba and Nadia Nijimbere opened this community-minded restaurant serving dishes from their native Burundi.

Concrete igloos standing across from what remains of the Michigan Central train depot.

Once the tallest building in Detroit, this Gothic church houses some of the oldest stained-glass windows in the country.

Mystic Incan rock piles three miles above sea level.

This 16th-century monastery was founded to cloister the daughters of wealthy local families.

Built on the remains of one the Incas’ most important gathering spots, this square keeps the spirit of a fallen empire alive.

This geometric feat is a testament to the Incas' mesmerizing architectural abilities.

A Christian monastery stands on what was once a holy Incan temple.

This Peruvian canyon is filled with geometric salt pools that have been being harvested since the Incan empire.

Huge stone depressions which may have acted as an Incan agricultural experiment.

Sleep in a glass pod dangling off a cliff.

Preserved Inca city and site of the last Inca stronghold against the Spanish conquistadors.

The intricate stonework of Machu Picchu serves as a testament to Incan engineers.

If you’ve ever seen a picture of Machu Picchu, then you’ve seen a picture of Huayna Picchu—you just didn’t realize it.

In the upscale neighborhood of Miraflores in Lima, a pretty little park is home to dozens of cats.