This Budapest bar allows drinkers to leave their mark on the walls, floor, and even ceiling.

A 19th century artistocrat's mansion, turned into a library, hidden in a modern library.

This smaller cousin of the Forbidden City has gone from ancestral sacrifice to tourist's whispers.

A bisected journey through evolution's history in the heart of Beijing.

This sensational Chinese temple walks visitors through the 76 weird departments of the afterlife.

Home to over 200,000 artifacts, this museum attempts to guide visitors through the ancient history of Beijing and Imperial China.

This ancient Chinese observatory still contains early astronomy technology.

This working replica of the 'Friends' coffee shop is more accurate to the show than the set itself.

This probably wasn't what Mao had in mind.

Beijing's World Park offers the excitement of international sites without the travel.

Ming Dynasty necropolis raided during the Cultural Revolution.

The most famous location in China was home to whole dynasties worth of imperial rulers.

Beijing's version of Disneyland, completely abandoned, mostly destroyed.

Beijing's expansive subterranean hiding spot now crumbles away as a tourist destination.

A vista of the city and sea from atop the little-known viewing deck on an unassuming Columbus statue.

A former steam-powered mill from the 1800s is now an industrial park with a giant steel dragon slide.

A temple to modernity, tucked away amid Barcelona's more well known museums.

18th century anatomical amphitheater of the Royal College of Surgery of Barcelona.

A stately palace has been converted into the world's largest cannabis museum.

Gaudí's famously flamboyant architectural style is on full display in this sprawling park and garden.

Mountain where Jesus was first tempted by the Devil.

Week-long block party becomes a competition for the best decorated street.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

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