This Norman castle has been the scene of assassination plots, religious persecution, and Nazi conspiracies throughout its long history.

Built by George III to observe the transit of Venus, this Georgian gem is a unique survivor in the Arcadian landscape of Richmond upon Thames.

The bust of a 15th-century Albanian leader in the middle of London.

One of London's lost rivers runs through a pipe over the tracks of this subway station.

A grand Wetherspoon pub set in a former opera house dating back to 1902.

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

This statue of one of the engineers who created the London Underground hides a ventilation shaft for the tube lines that run under the street.

It’s fun to stay at the YMCA… but at this London outpost, it’s even more fun to eat the Bombay aloo.

The secret wartime bunker built on the platforms of an abandoned Tube station.

William Smith's iconic "map that changed the world" is hidden behind a curtain in the Geological Society building.

This London pub hides a peculiar secret: a recreation of the rooms shared at 221b Baker Street by Sherlock Holmes and Dr. Watson.

The first regular high-definition TV transmissions were made from this seemingly out-of-place mast located on one corner of a Victorian-era entertainment venue.

This peaceful park with centuries of history hides in an overlooked section of South London.

This iconic high-rise residential block was one of the last to be built in the Brutalist style.

This bookstore serves recipes from the cookbooks on sale.

Catacombs turned marketplace.

Visit the grave of a famous feminist author and the mother of Mary Shelley.

A Victorian school for poverty stricken waifs has been preserved as a museum to their donated education.

A historic London cemetery now serves as a nature park incorporating gravestones & memorial statues.

This hydraulic power system in London was, at one time, seen as a rival to electricity and the last of its kind to shut down.

A museum that chronicles the interesting and often dark history of the London docklands, once one of the major trading ports of the world.

This sculpture of a pylon is upside down and askew, as if its main purpose is to confuse passersby.

A musical composition 1000 years in length plays at the Trinity Buoy Wharf in London.

A replica of the gaslit streetlamp under which three teenagers founded a football club.