This remote desert watering hole has a connection to a curious chapter of American history.

An incredible airplane graveyard sits outside this small museum dedicated to preserving aviation history.

This charming colonial alleyway is one of the oldest continuously used residential streets in the U.S.

The pretty iron lamp is a reminder of the architecture underneath London's streets.

This stone quarry was used to make axes and other tools more than 6,000 years ago.

This structure atop a craggy cliff in one of the most beautiful parks in Paris boasts an unbeatable view.

The commemorative stone column conceals a secret laboratory.

The most southern point you can drive to in the Western Hemisphere.

A tiny replica of the iconic London landmark hides on the side of the steel structure.

The narrowest street in Paris.

This riverside restaurant has been serving customers since 1146.

Revel in the Victorian splendor of the world's oldest eating establishment inside a museum.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

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

One of the most spectacular bridges in Spain spans a narrow chasm that divides the city of Ronda.

A little-known ruin with a convoluted history and a fascinating latrine drainage system.

This centuries-old wooden wonder was built in less than a year and is one of Europe's largest timber-framed churches.

L.A.'s oldest operating bowling alley is a beautifully restored homage to its speakeasy days.

A beautiful ruin of a 14th-century Plantagenet castle built by a medieval mercenary.

Despite its grandiose name, this enigmatic first-century void under the town is no cave, and it's possibly not a palace either.

The extensive relics of an ancient Roman and Phoenician fish processing plant hide in a town park.

The smallest museum in Basel, Switzerland, is a two-foot-by-two-foot window in the door of a 600-year-old house.

The verdant mossy ruins of a Franciscan monastery lie in the remote Sintra hills awaiting exploration.

An engineering error ensured this cavernous 350-foot-long subterranean thoroughfare was never used as intended.