One of the figures in this Celtic sculpture continues to puzzle archaeologists.

This Viking gravestone carved in a rare runic style was dug up from a London churchyard.

A living memorial to the trees London lost during the Great Storm of 1987.

Tucked away in the Tower of London is the weapon once used to execute high-profile prisoners.

The "lost friend” is the most famous of the six moai statues that were removed from Easter Island.

A Roman spa buried deep beneath the City of London.

These official units of measurement—including chains and perches—lie hidden beneath tourists' feet in a popular London hub.

A statue of the legendary Celtic warrior queen who fought the Roman invaders stands in one of the cities she once destroyed.

The watery entrance for condemned prisoners heading to the Tower of London is still visible along the Thames.

Six ravens are kept captive (but well-fed) at the Tower of London to prevent the fall of the Crown.

The Metropolitan Police refurbished the blue box (perhaps not coincidentally) the same year "Doctor Who" returned to TV screens.

A naturally mummified 2,000-year-old man.

An small and easily overlooked archaeology museum chock full of Egyptian artifacts.

Mary Kelly was last seen here before she was murdered by Jack the Ripper.

Thanks to modern navigational tools we now know that the true prime meridian runs through a park next door.

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

A historic London pub with prison cells in the cellar and a "spy room" on the second floor.

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

Eighty million natural history specimens call this gargantuan museum home.

Rebuilt remains of a temple to Roman god Mithras.

An unusual round church in London with a Templar past.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the Harry Potter films.