This legendary stone is of unknown origin, and throughout history has been a literal touchstone for British leaders.

A 2000-year-old Roman amphitheater lies just below Guildhall Yard.

This may be the last of London's wooden pavements, which were once a common sight in the city.

It's a mystery why these remains were found with no traces of their bodies in sight.

The gigantic skull of a long-extinct species that once roamed the forests of England and Ireland.

Public access to clean drinking water was an instant hit among the masses.

This churchyard arbor is surrounded by hundreds of gravestones placed there by author Thomas Hardy.

The Art Deco artwork depicts gilded carriers of deadly illnesses.

A performance hall at the American Jewish University moonlights as a sci-fi film location set.

This vintage car parts store is also a museum devoted to a squat little gem of automotive history.

At this Denver landmark, the meals are compulsory, the sopapillas are complimentary, and the insanity is everywhere.

The marker offers a rare chance to be in four U.S. states at once, though there's some controversy over its geographic accuracy.

The ancient dwellings of the Puebloans, located in the cliffs of majestic mesas.

A breathtaking array of ancient Pueblo structures and artifacts counterintuitively preserved by neglect.

This once-popular otherworldly landscape was formed by one of the largest volcanic eruptions in history.

The world's tallest turtle riding the world's largest snowmobile.

One man's quest to save his town with a trail of record-breaking sculptures.

The sun acts as a key that only fits this giant keyhole twice a year.

This tiny patch of arid sand sits in one of the greenest states in the United States.

An abandoned 1970s theme park that has been turned into a space for waterfront walking.

Little island known for its massive beachfront "flowerpot" pillars.

This natural sea cave hides a small wonderland of natural turquoise beauty.

This lone tree and dramatic sandstone outcropping are so beloved by Michiganders they can be found on one of the state’s coins.

This little barrel-shaped cottage by Lake Superior was once a cartoonist's summer retreat.