Roman ruins top white travertine terraces formed by ancient hot springs.

A small, emotionally charged room inside the Mario Testino Museum dedicated to Princess Diana and one famous photo shoot.

A fascinating little museum all about the rich history of Peru’s famous plant.

The mysterious "Candelabra of the Andes" could represent anything from a god's trident to a hallucinogenic plant.

An unexpected desert oasis in South America.

The stones of this Incan wall complex fit together so well you couldn't fit a piece of paper between some of them.

A set of ancient drawings in the desert of Peru that are so massive, many of them can only be fully seen from the sky.

A remote candy-striped mountain in the Peruvian Andes straight out of the pages of Dr. Seuss.

This incredible college library is a visual masterpiece of mosaic art. It also looks kind of like a giant boombox.

The famous artist couple lived and worked here, in two different houses separated by a bridge.

The only castle in North America to ever house European sovereigns.

Gilded heaven for philatelists and architecture freaks, still in full working order despite sitting atop tremulous ground.

A museum in the former home of Marxist revolutionary Leon Trotsky.

66,000 pieces of art, donated by one of the world's richest men.

Part bookstore, part café, and part forest.

Frida Kahlo's childhood home, now a museum of her life and works.

An island filled with hundreds of hanging, decomposing, decapitated dolls.

The world's longest outdoor covered escalator system transports commuters through Hong Kong's hilly terrain.

Teeming with illegal goods and services, this towering maze of vice is also a popular tourist accommodation.

This hulking behemoth is actually five interconnected towers built in the 1960s.