The Tudor-style cottage in the middle of the square is not quite what it seems.

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

Sculptor Antony Gormley used chaos theory and fractal growth to design his tallest creation.

A mysterious shape catches the eye in this 16th-century painting.

This ornate Victorian marketplace was the setting for Diagon Alley and the Leaky Cauldron in the first ‘Harry Potter’ film.

The perfectly preserved underground rooms where Churchill plotted the war against Germany.

The curios of pharmacist and collector Henry Wellcome.

An unusual round church in London with a Templar past.

The signs of a long buried road can still be found hidden beneath a London sewer grate.

Hear the quietest sound from across the dome.

London's old-school healing garden.

Scattered throughout London are ancient remnants of the city's former bounding wall.

Eighty million natural history specimens call this gargantuan museum home.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

A community of artists and entrepreneurs seeks a simpler life on London's waterways.

You'd never know the houses at 23-24 Leinster Gardens were fakes—until you see the train tracks on the other side.

A Roman spa buried deep beneath the City of London.

Richard III supposedly disposed of his nephews' bodies here in an effort to seal his claim to the throne.

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

These mysterious Viking chess pieces spent centuries hidden on a remote Scottish island.

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

London's last remaining public soapbox site has seen speeches from Karl Marx, Vladmir Lenin, and George Orwell.

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

Pop culture has helped to keep this iconic British building from being destroyed.