This astonishingly geometric cave has inspired everyone from Jules Verne to Pink Floyd.

During prohibition, corrupt city officials ran drinking dens under the streets of Downtown Los Angeles.

Numberless clock creates a meal of time for the dreaded, insectile Chronophage.

Ancient Egyptian wigs, South American feather headdresses, a bounty of anthropological artifacts in Oxford.

A 26-foot shark sculpture—a statement about bombs—set off a municipal battle royale.

This concept building is the UK's first attempt at making a permanent structure of nothing but trash.

Both church and state get put to the torch in this annual festival in the "Bonfire Capital of the World."

360° views of the city plus five floors of optical illusions and hands-on science.

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

A metal tree emits eerie, melodic notes on top of Lancashire's Crown Point.

A giant wooden soda bottle pays homage to a distinctly British drink on the very spot where it was invented.

Don't worry, they don't use antique scissors.

A museum wholly devoted to juvenescence.

A special shop catering to the needs of things that go bump in the night, and also helps kids become writers.

A comic book store that puts the marvel back in marvellous.

The site of London's first coffee house has been serving refreshments of one kind or another for 360 years.

A quiet memorial to those who died saving others in the heart of the City of London.

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

Since 1874, this macabre collection has developed into a museum devoted to Scotland Yard's mementos of dastardly deeds.

A roadside shrine to a late rock god only remains thanks to the unyielding efforts of his fans.

Vast stretch of tide-pools with a unique Moroccan charm.

This controversial Irish show cave is home to a massive formation known as the Great Stalactite.

Shipwrecks, ruins, and turtles are all that remain on this haunting Caribbean ghost island.

Numerous impressive carvings are embedded in the trees lining this street in Marrakech.