The highest peak in Wales is said to be the final resting place of a giant killed by King Arthur.

A subterranean playground in an abandoned slate mine.

An amazing collection of curiosities hidden in a small Welsh village.

Overlooking the burial ground is a tower designed to prevent thieves from snatching the recently deceased.

This alley off Edinburgh's Royal Mile contains remnants of the city's seedier history.

A 18th century graveyard and its astonishing cortege of macabre iconography.

Possibly the world's smallest museum is home to one exhibit that sheds light on the capital city's dark criminal history.

This historic pub has maintained much of its 1906 decor, including a small sequestered room for women, where orders were slipped through a tiny window.

A book bound in the skin of an infamous criminal, along with countless other specimens.

A church that bred legends, and served as an inspiration for the Da Vinci Code.

360° views of the city plus five floors of optical illusions and hands-on science.

This tunnel entrance is built to resemble a grand castle but no one is quite sure why.

A Victorian park cemetery, standing on the site of what was once the Great North Wood.

A cluttered and astounding collection of antiquities and curiosities.

Decrepit Victorian public lift is a white-knuckle ride.

One fisherman has used his love of pebbles and shore to create a crazy garden of rocky art.

This English medieval castle is where King John died of dysentery.

The remains of Crystal Palace Great Exhibition of 1851.

Despite attempts by local police to discourage it, Beatles-inspired graffiti has been a means for artists to air grievances for decades.

These "anatomical machines" are only one of the many strange items in this Italian crypt.

A labyrinth of ancient tunnels hidden below the city holds the ruins of 2,500 years of history.

Dug as a secret royal escape route, the tunnel became a wartime bomb shelter and dumping ground for vintage cars.

Skulls from the plague of 1656 and World War II bombings are united by a cult dedicated to caring for the ancient dead.

An underground paleo-Christian burial site composed of the remains of several cemeteries and Basilicas.