This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

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

Tiny effigies of the victims of Edinburgh's famous Anatomy Murders.

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

"Respectful to the dead, safe and sanitary to the living, dedicated to the Genius of Memory..."

This Scottish bridge seems to compel dogs to leap to their death.

This antique prison is a tourist attraction with a sordid past.

Half-eaten food on display at an English café.

The world's largest collection of witchcraft regalia.

This grave resides at the crossroad of three parishes.

A house of bones — but nobody is quite sure to whom they belong.

Once thought to be the mysterious work of a witchy prophetess, a well with unusual properties turns objects into "stone".

One family's environment-friendly hobbit-house in Wales.

The world's smallest movie theater runs on solar power—an attraction in itself.

The breadfruit-adorned final resting place of the infamous Captain of the HMS Bounty.

This shop and gallery is a modern-day cabinet of curiosities, unassumingly positioned along an urban thoroughfare.

The anatomical-pathological collection of a man who changed surgery.

The curios of pharmacist and collector Henry Wellcome.

London's creepiest cemetery was once the site of dueling magicians and mobs of stake-carrying vampire hunters.

A 200-year-old prison that now houses a peculiar crime museum.

"The Most Wonderful Wonder that ever appeared to the Wonder of the British Nation."

An intriguing three-sided folly is a testament to one man's devotion to Catholicism and the number three.

A landscape decorated with enormous skull sculptures.

The headless bodies of more than 1,300 guillotined victims of the Reign of Terror are buried here in mass graves.