Once considered one of the country's finest motte and bailey castles.

This plaque commemorates an amazing 19th-century sea rescue.

This coin collecting cod is over 130 years old, and the United Kingdom's smallest listed structure.

The sculpture is made of more than 100,000 knives collected to raise awareness about violence.

This tidal island, a sacred site in early English Christianity, was the target of a notable Viking invasion.

A Brutalist monument in the middle of a housing estate by artist Victor Pasmore.

On this small spit of land, the person who runs the public house is considered the King of Piel Island.

Over a decade ago, painted penguins mysteriously appeared around Berwick-upon-Tweed for no apparent reason.

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

The experimental test tracks of a retro-futuristic monorail still stand in the French countryside.

This 1,300 year old monastery built atop a single rock was once only accessible depending on the whims of the tide.

Heralded as the oldest statue in London.

Tucked away behind the mansions of Mayfair, this picturesque garden is a hidden London treasure with a spooky past.

This overlooked street light once served as a KGB dead letter box.

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

This once-controversial and slightly confusing statue of Achilles was built out of captured cannons.

Legend says these colorful, invasive residents are the descendants of birds released by Jimi Hendrix.

Never actually a tree at all, this spot was the site of London's public hangings for nearly 600 years.

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

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

This five-star hotel was originally a swanky parking garage.

It is still illegal to "quarrel" at this unlikely urban oasis built on top of an electrical substation.

A plaque marks the underground site of one of London's "lost rivers."

This London marker celebrates the spot where the world-famous English band was founded.