Wedged between two buildings at the Great Ormond Street Hospital is this secret music installation.

A 1,215-foot tunnel transports pedestrians beneath the River Thames.

The curios of pharmacist and collector Henry Wellcome.

An unusual round church in London with a Templar past.

A tongue-in-cheek arcade where the games are based on everyday life.

The popularity of Sherlock Holmes led to the creation of his fictional address, turning the orderly London street numbers askew.

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

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

The oldest inn in Kilkenny was established by the first convicted witch in Ireland.

Local legend says the remains of Father Christmas lie within the medieval grounds.

The oldest pub in Ireland may also be the oldest surviving bar in the entire world.

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 eccentric garden of sculptures crafted in India decorate an Irish green space dedicated to Alan Turing.

The world of the ancient Celtic civilization explained through a bewitching 11 acre garden.

A tiny microvalley etched into the side of Knocknarea Mountain hides another world.

This Irish show cave is said to have been the site of a Viking massacre that claimed 1,000 lives.

The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.