In Twickenham sits a small whitewashed castle that inspired Mary Shelley's 'Frankenstein.'

An English artist has turned an unassuming ex-council house into a time-lost house of mystery.

This Gothic Revival castle used as a shooting location for "The Secret Garden" and other films.

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

St. Mary's Asylum was isolated and abandoned before being converted into a Bed and Breakfast.

Grab a cuppa at England's first and only domestic tea plantation.

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

Below a historic English market town lies a secret underground city complete with kitchens, laundries, storerooms, and an underground lake.

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

Mysteriously stacked storefront paths give this medieval British town an iconic style like none other.

A Victorian natural history and ethnographic museum with wonderful turn-of-the-century, science-book-esque evolution displays.

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

A vast overgrown cemetery, once known as one of London's "Magnificent Seven."

A student driver's nightmare.

A subterranean ice warehouse that has lain hidden beneath central London for over a century is now open to the public.

The hidden "ballroom" under a mansion lake was built by a criminal who ate a cyanide pill during his trial.

The world's largest collection of witchcraft regalia.

The sign at the garden gate reads: "These Plants Can Kill."

The mysterious, fantastical woodland inspiration for "The Lord of the Rings."

When the plague struck York, this stone was used to leave supplies for the sick.

Makers and sellers of the original and finest York Ghosts.

The ghosts of Britain's telecommunication past sit rusting away in a small village in England.

The remains of a remote village that once housed over 1,200 dam workers and their families.

A dramatic sculpture high up in Yorkshire with vistas on an industrial scale.