17th century streets hidden under Edinburgh were once a breeding ground for the black death.

This 18th-century fort surrounded by a moat was used to store gun powder and ammunition, and now sits in the middle of a large part in Dublin.

This supermarket offers shoppers a window into the past alongside their groceries.

A mysterious plaque to the even more mysterious "Fr. Pat Noise," killed in "suspicious circumstances."

After it was swallowed by a Georgian mansion, this medieval castle remained forgotten for centuries.

This is the largest cemetery in Ireland and the first cemetery museum in the world.

The block of aged dairy is probably still edible after 2,300 years in a peat bog.

The enchanting archway is the only surviving portal into Dublin's lost medieval wall.

An 80-year-old plane tree is devouring an iron bench at Ireland's oldest law school.

This permanent collection of preserved bodies taken from Irish bogs is one of the leading authorities on such morbid mummies.

One of Ireland's most infamous prisons for rebels including men, women and children.

A museum that cashes in on its infamous little people while teaching you a thing or two about the Irish fey.

An Irish church where an 800-year-old mummy is reaching out of his coffin as if to shake hands.

An unsanctioned shrine that sprung up outside the late singer's home is causing a stir in London's Highgate neighborhood.

A traditional American farmhouse plopped in the middle of a Piccadilly courtyard.

An abandoned tank sits in an empty London lot as a symbolic middle finger to local city planners.

This plaque in one of London's oldest public hospitals commemorates the first meeting of two of Britain's most famous literary heroes: Sherlock Holmes and Dr. Watson.

One of London's oldest houses contains a mixture of both old and modern features.

Preserved behind glass, the ruins of a medieval building used to store human remains.

A mineral spring that became all the rage in 17th-century England.

A giant scrawl on the skyline of south London.

This unassuming alcove in London’s famous Tower Bridge once served to capture, store, and display dead bodies from the River Thames.

According to legend, this tomb holds the secrets to time travel.

This striking statue brings a scene from the African savannah into central London.