The ruins of an 11th-century Norman castle with a rare, perfectly circular shape.

The anatomical-pathological collection of a man who changed surgery.

A unique tribute to the millions of animals who served and died for the British military.

Originally built for London’s cab drivers, this bright green hut now serves anyone a hot drink or meal.

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

The broken skateboards that became a poignant memorial to a murdered skater.

A recently restored Shoreditch landmark with ties to Jack the Ripper.

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

Children's hospital in London that operates on royalties received from Peter Pan, which J.M. Barrie signed over in 1929.

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

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

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

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

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

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

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

Public access to clean drinking water was an instant hit among the masses.

A statue marks the exact spot where The Boy Who Never Grows Up made his first literary appearance.

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

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

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

Giant, friendly pelicans in Central London, the most unlikely of places.

The sixth of London's "Magnificent Seven" cemeteries, and a source of unlikely inspiration to Beatrix Potter.

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