One of the few standing Roman lighthouses and a labyrinth of tunnels are a couple of the secrets at this historic castle.

This picturesque horseshoe weir was first built in the 1600s to prevent flooding in the town of Bath.

At the center of London’s oldest roundabout stands an obelisk that was erected in 1771, but spent several decades elsewhere.

Once designed as the entrance to Buckingham Palace, this structure was later relocated and stands as a victory arch.

A memorial for public executions that dates back to the 14th century.

Chelsea's soldiers were given strict orders when crossing this historic bridge.

This Underground station has been a popular filming location for decades, even before it closed.

A gallery specifically dedicated to the botanical illustrations of a remarkable traveling lady.

The London statue that imitates passersby.

The bronze uniforms commemorate the vital role of women during World War II.

Shiny Brutalist box commemorates a pioneer of electricity and houses a railway transformer.

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

An architectural oddity hides in plain sight on this iconic London bridge.

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

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

The library houses an incredible collection of some of the world's most impressive books and manuscripts.

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

The largest of London's subterranean rivers and once a mad, bad center of London life.

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

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

After nearly 60 years, there's still a bear at Paddington Station looking for help.

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

A cluttered and astounding collection of antiquities and curiosities.

Kings Cross Station pays tribute to its role in Britain's best-selling book series.