This tiny little pool is said to be home to a malicious mermaid named Jenny Greenteeth.

This small collection of rare books was uniquely locked up for safe keeping.

One of the few standing Roman lighthouses and a labyrinth of tunnels are a couple of the secrets at this historic castle.

The remains of the great moral philosopher reside in a university in London.

This hospital once pioneered the use of electroencephalograms, but fell into maltreatment, abuse, and eventual abandonment.

This allegedly haunted 16th-century tower house-turned-museum exhibits thousands of spectacular objects.

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

This romantic, decaying 13th-century ruin on the edge of Sherwood Forest is reputedly one of England's most haunted places.

A giant pineapple, a symbol of hospitality, and an amazing vacation rental option.

One of the largest sculpture collections in the U.K. features history's greats, from Bob Dylan to Galileo, in bronze.

The stately remains of Llywelyn the Great's mighty fortress.

Two plaques commemorate the site of Shakespeare's first theatre.

This Manchester laundromat is hiding something.

This colossal war machine is now a living museum dedicated to underwater warfare.

Obscene versions of this artist's work are the most popular.

This haunting stone chasm is a hotbed of mossy rock and English legend.

This foolish Victorian sea fort was converted to a deluxe hotel.

The mystery of this small, brick pond eluded its possibly only investigator until his death.

A historic Georgian building and warm springs.

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

Charles Babbage's proto-computer, painstakingly brought to life.

This cramped crevasse saw the entire population of its island suffocated inside its depths.

The John Snow Memorial marks the epicenter of London's 1854 cholera epidemic.

Near the former site of numerous witch burnings, this lavish Edinburgh mainstay pays homage to Scotland's brutal history.