The deepest spring in Missouri.

Once an ambitious nature spa, these forest ruins now provide a serene monument to failure.

An average of 33 million gallons of water pour out of the collapsed cave at the heart of this spherical spring.

Rebuilt remains of a temple to Roman god Mithras.

Preserved behind glass, the ruins of a medieval building used to store human remains.

Banksy gives themself artistic license with this piece of London street art.

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

Fascinating town where normal life interfaces with the occult.

This hill and tower are steeped in legend, from King Arthur to the Holy Grail.

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

In the ruins of Glastonbury Abbey lies the alleged resting place of the legendary king.

Perhaps the only prehistoric monument with its very own public bus stop.

A holy well supposedly infused with a saint's spirit flows within this quaint chapel.

Now nearly dry, this lake is said to be the ancient home of the Lady of the Lake, and was once thought to be bottomless.

A island reachable by a causeway at low tide is possibly one of the earliest Western European locations to be identified in text.

A unique waterfall that some believe attracts the fairfolk.

A 6th-century stone lies at the site of the mythical battle waged between King Arthur and his nemesis Mordred.

One of England's most famous churches hides a pair of little known architectural treasures.