This tiny river island switches sovereignty every six months as part of a rare, centuries-old agreement.

In this historic region, homes and churches are carved into ancient volcanic rock formations.

Thousands of well-dressed mummies below a monastery.

Hidden beneath the streets of London is a secret subway that only carried mail.

Thousands of exquisitely carved stone water storage wells, hundreds of stone steps fill this exquisite medieval stepwell.

The largest of London's subterranean rivers and once a mad, bad center of London life.

Try not to get slimed in Tribeca.

The birthplace of an eccentric alchemist and possible inspiration for the fictional reanimator of monsters.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Staves, storm-calling, and of course, necropants.

The only structure left with direct ties to the Salem witchcraft trials of 1692.

A walk through the historic city center, under the streets of Seattle.

A trash dump made beautiful by nature's power.

A snapshot of the city's fascinating voodoo culture.

This jaw-dropping 19th-century bridge uses its reflection to form what appears to be a perfect circle.

The real life Hobbiton, this sheep farm has been forever transformed since being built for The Hobbit film series.

This Boston medical museum features the skull of the famous medical case of Phineas Gage.

Dodge prohibitionists and slide through the telephone booth in Crif Dogs.

The history of occult science is turned into a creepshow at this lurid Prague tourist attraction.

A massive underwater sinkhole made famous by Jacques Cousteau.

The fairy tale castle of the "fairy-tale king."

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

An ancient capital city that dates back 3,000 years old and harbors many surprises.

The rocks in this arid basin leave trails of movement behind them.