The 2,000-year-old beam is tucked within the pedestrian entrance to the old London Bridge.

A portly statue of a golden boy commemorates an unusual cause of the Great Fire of London: the sin of gluttony.

The last remaining example of the boatmen's perches that once dotted the south bank of the Thames.

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

The last four extravagant street signs of London's historic banking street.

This one has sailed five times as far as Sir Francis Drake's famous ship.

The lab where the scientist made his groundbreaking discoveries is preserved on the basement floor of the Faraday Museum.

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

Graffiti from the 16th and 17th centuries cover the walls of this part of the Tower of London.

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

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

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

Charles Babbage's proto-computer, painstakingly brought to life.

Repository for more than 22 million pickled specimens.

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

A charming 17th-century alley is lined with secondhand bookstores and antiquarian shops.

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

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

Eighty million natural history specimens call this gargantuan museum home.

Catacombs turned marketplace.

Rebuilt remains of a temple to Roman god Mithras.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

A special shop catering to the needs of things that go bump in the night, and also helps kids become writers.

The curios of pharmacist and collector Henry Wellcome.