The seaside ruins of an ancient salt production facility.

This tall stone wall with no door and ill-matched windows was built centuries ago, and used as a shelter for domesticated pigeons.

A museum dedicated to Wales’ favorite—and strangest-looking—watercraft.

According to legend, King Arthur killed a beast that dwelled beneath the waters of this Welsh lake.

A modest stone circle in North Wales.

Led Zeppelin wrote some of their most iconic songs at this little 18th-century Welsh cottage.

This former military airfield's claim to fame came from a lucky accident during the Second World War.

A rocky sea serpent hides caves, blowholes, and a spectacular natural bridge.

Centuries of human activity have forged an eerie landscape of ruins and craters on an exposed and windswept hilltop.

The largest known medieval map of the world.

This theater opened in 1998, but both the building and the puppeteers who perform there have a distinguished history.

The collection is exhibited in a Staten Island building modeled on traditional Himalayan architecture.

An aptly-named street near the birthplace of the modern LGBT rights movement.

An underground mansion with fruit-bearing trees and grapes growing beneath the surface of central California.

A psychedelic labyrinth on the San Francisco bay.

Quite simply the largest tree in the world (by volume).

Four hundred granite steps were built into this massive rock by the National Park Service.

A hyper-luxurious, 12,000- square foot home might be buried beneath Queens, still waiting to protect you from nuclear missiles.

This garden located inside a bamboo forest once belonged to a famous Japanese actor.

The longest spit in the United States ends at a lighthouse in the Strait of Juan de Fuca.

Enjoy dishes that founding fathers once ate at this Colonial Williamsburg pub.

The longest step street in the city.

This pub boasts a curious history and may have inspired a Dickens character.

Amid skyscrapers and traffic exists this unique aquatic ecosystem.