An abandoned water sports stadium that has become a haven for graffiti and decay.

Where monkeys run wild and the humans are caged.

This historical swimming pool near Miami is emptied and refilled each day with naturally filtered water.

San Francisco's newly reopened hands-on science museum.

A raised boardwalk winds through a thicket of stunted, century-old trees no more than nine feet tall.

A local dialect born in the late 19th century is only spoken in this isolated California valley.

This Oakland fairytale kingdom, fiercely devoted to childlike whimsy, was an early inspiration for Disneyland.

Legend says if you stick your thumb in the hole and it gets wet, your wish will be granted.

A section of the long chain that blocked enemy ships from entering Constantinople.

No one is sure if the world's fourth-largest diamond had been found in a rubbish heap or was pawned by Napoleon's mom.

1513 Turkish world map, full of European state secrets and snarky commentary.

Breathtaking and huge 430 year old maps of Italy.

Hidden beneath the famous St. Peter's Basilica is a veritable city of the dead that may hold the remains of St. Peter himself.

Historic fortifications form the boundary of Vatican City, but it’s not entirely surrounded by walls.

The Pope’s secret escape route.

This ancient Roman bridge and aqueduct still stands as a wonder of classical construction.

Peek through the gates at this oasis from the city, full of Old English charm.

This Upper East Side apartment co-op was designed as a tuberculosis sanitarium.

J.R.R Tolkien, C.S. Lewis, and other "Inklings" met at the Oxford pub to discuss the now legendary fantasy stories they were writing.

This nondescript building was the birthplace of Morris cars.

This slice of 1960s Danish modernism does not conform to the Oxford college stereotypes.

Legend says this public grazing area hasn't been plowed for thousands of years.

The spot where Oxford garnered its name was also home to a medieval philosopher and includes a house covered in statues.

The spot where three Protestant clergymen were burned at the stake during the reign of "Bloody Mary."