An engineering error ensured this cavernous 350-foot-long subterranean thoroughfare was never used as intended.

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

This observatory within Europe's first dark sky park offers stunning views of the night sky.

A century-old tradition has culminated in a small but singular collection of feline effigies.

Follow the original medieval paths that wind through this intriguing section of the city.

The remains of a grand castle that may have inspired Bram Stoker's Dracula.

Britain's only herd of free-ranging reindeer.

Long abandoned underground complex to keep royals safe from a nuclear war that never came.

A open air theatre built on a cliff by an eccentric British woman.

This Manchester laundromat is hiding something.

Dating back almost 400 years, the oldest public collection library in the United Kingdom was once the study hall of Karl Marx.

England's oldest surviving hedge maze has been confusing visitors for over 300 years.

The highest peak in the United Kingdom has a history of physics, specters, and a pilgrimage of strange objects.

A collection of comics, graphic novels, animation and caricatures devoted to exploring this often overlooked art form.

Hidden in a grotto 26 feet below Nottingham's oldest hotel, this stylish subterranean drinking den is notoriously hard to find.

The ruins of this gorgeous clifftop castle look like something from a fantasy novel.

The gloomy ruins that inspired Bram Stoker to bring Dracula to life.

Famously misunderstood wonder of the ancient world

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

This peculiar Italian elevator runs both horizontally and vertically.

The secret medieval communication system will whisk your words above the noise of the crowd.

Milan's duomo is covered in beautiful carving including a curious "dinosaur-like" beast.

Small on the outside, big on the inside, this church is an astonishing act of visual deception.

Two very green residential towers cleaning the air in one of Europe's most polluted cities.