One of the largest mechanical models of the solar system in the world.

A treasure trove of astronomical, mathematical, and scientific instruments at Cambridge University.

A medieval replica of King Arthur's legendary table, the Round Table hanging in Winchester Castle was decorated by Henry VIII.

No one knows who created the statues or if they are arranged properly—let alone the artwork's real name.

Enormous terracotta heads of Queen Elizabeth and Prince Phillip can be seen on the side of the road to Windsor.

A 6th-century stone lies at the site of the mythical battle waged between King Arthur and his nemesis Mordred.

A mysterious crater-like pond has a spooky tendency to empty and fill with complete disregard to rainfall patterns.

Three small rooms at the back of the “official” church of London's clowns.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

This 80-year old mannequin is so lifelike it is believed to be an embalmed corpse.

This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

A rotating cast of guys and dolls in front of a Washington, D.C. building.

This narrow shop in the East Village hosts a matchmaking service for the new millennium.

One of the last full-orchestra recording studios in New York City and an acoustical marvel.

The former hotel where Tesla invented the radio.

During the holidays, a vintage subway train whisks New Yorkers back in time.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.

A hands-on traveling collection of the innovative devices of yesteryear.

A monument in Washington D.C. marks the spot from which all other roads were supposed to stem.

The site of the climactic scene from the classic horror film is now a historic landmark.

Hidden in plain sight on a pair of Manhattan subway tunnels are a pair of public instruments that sing to each other.

The slender brass strip in Prague's Old Town Square was used to tell time from 1652 to 1918.

This doorless 20th-century elevator doesn't stop or slow down.

More than 300,000 historical artifacts from the famous music venue, from Duke Ellington's handwritten score to The Beatles' booking slip.