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

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

19th-century scientists would make the pilgrimage here to verify the precision of their measuring sticks.

This London plaque marks the spot where David Bowie's famous alien made his debut.

This beautiful Victorian ironwork masterpiece was built to keep London from smelling like poop.

A clock designed to run with perfect accuracy for 10,000 years.

A Roman spa buried deep beneath the City of London.

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

Hidden behind a wall for decades, this masonic lodge was only rediscovered during renovations.

London's old-school healing garden.

A network of concealed passageways lies within a busy London Underground station.

London's smallest police station is barely the size of a phone booth.

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

A cluttered and astounding collection of antiquities and curiosities.

This hidden green space is the city's second largest conservatory.

The final resting place to 300 Victorian-era pets hides inside the city park.

An incarceration museum on the spot of possibly the oldest prison in England.

The site of London's first coffee house has been serving refreshments of one kind or another for 360 years.

A little slice of Japan and its aesthetics in London's Holland Park.

Catacombs turned marketplace.

Rebuilt remains of a temple to Roman god Mithras.

This 1920s Dutch barge is now a floating bookstore.

Winding paths and ramshackle mausoleums in the oldest "park cemetery" in London.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.