A multi-storied adobe complex has been inhabited for more than a thousand years.

The site of murders and Satanic cult gatherings.

Mysteriously stacked storefront paths give this medieval British town an iconic style like none other.

Yale University's home for rare works, including the mysterious Voynich Manuscript.

The last moments of the ill-fated Pompeiians, frozen forever in plaster.

Scattered throughout London are ancient remnants of the city's former bounding wall.

Costumed elves and mountain bikers co-exist peacefully at this abandoned Christmas-themed adventure park.

These azure waters were thought to lead to the Mayan Underworld.

Legends surround this jagged rock formation in the New Mexico desert.

This expansive bridge in the Canadian wilderness was originally just built for friends.

The glowing blue Nymphaeum of Emperor Tiberius.

By day this New Orleans square is for pedestrians, but by night it is a kingdom of kittens.

The final resting place of a space program monolith.

This Florida sinkhole hides a rainforest-like micro-environment in its depths.

The largest drain hole in the world.

In a city filled with Frank Gehry buildings, one stands out as one of the architect's weirder works.

A large grotto built in the 16th century amidst Florence's famous Boboli gardens.

The former home of the Nobel Prize-winning American writer is now home to dozens of six-toed cats.

The doodles of a genius line the walls of a secret room under the Medici Chapel, where they were hidden for nearly 500 years.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

The eccentric mansion of one the most popular horror authors of modern times.

The oldest operating pharmacy in the world features 800-year-old recipes.

2300-year-old Roman road connecting the empire.

The highest bridge in America was built for an almost unnervingly small amount of money.