Although it appears ancient and mysterious, the quirky folly was actually built 200 years ago by an eccentric estate owner.

An artistic tribute to the famous singer, just around the corner from where he was born.

This lovely little burbling creek is actually a deadly waterway that has dragged down everyone who ever set foot in it.

Now famous as the "Harry Potter bridge," this impressive concrete viaduct has long been an icon in its own right.

The intended purpose of this unfinished Elizabethan building remains a mystery.

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

This medieval sanctuary's tree-framed door looks like a portal to a mythical realm.

This mysterious underground cave in Shropshire dates back to the 18th or 19th century.

The storied English village that pretended to be insane inspired NYC's nickname and the fictional namesake in the DC Comics universe.

Under a church hides a forgotten 13th-century ossuary containing the remains of around 2,500 people.

Built by the patron saint of illusionists this Elizabethan manor house is riddled with secret cubbies for hiding priests.

The alleged birthplace of Lady Jane Grey, who was executed at age 16 for claiming the throne of England.