Ruins of a German Castle on top of a towering stone pillar.

In all of the 29 years it was in operation, no prisoners ever escaped successfully... or so they claim.

A white Buddhist temple with a golden restroom.

17th century streets hidden under Edinburgh were once a breeding ground for the black death.

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

Once thought to be the mysterious work of a witchy prophetess, a well with unusual properties turns objects into "stone".

One of the largest caves in the world open to the public.

Machismo turned on its head: the lady's hand goes to the dude with the bigger brain.

A modern sliver of architecture in Roma.

A mud volcano in Indonesia spews out 50,000 cubic meters of mud every day.

Stunning wetlands ablaze with pink lotus flowers.

World's largest cave was only discovered in 1991, and now offers tours to the public.

An outdoor sculpture park of giant pink robots and post-apocalyptic Christmas scenes.

An eclectic trailer park retreat in the middle of the California desert.

One of the largest, oldest, darkest, quietest motel rooms in the world.

"Only the devil could play golf here."

Stepping away from the glitz of mobsters and casinos to learn about the other history of Vegas.

Dyed by iron oxide over centuries, these sandstone rocks rise thousands of feet into the sky.

A burnt orange monolithic dome structure perched on a hillside near Interstate 280.

An artsy hidden staircase leads to breathtaking views of San Francisco.

Olfactory delights in San Francisco's Botanical Gardens.

A hyper-luxurious, 12,000- square foot home might be buried beneath Queens, still waiting to protect you from nuclear missiles.

Curious crustaceans support an obelisk from ancient Egypt that now stands in modern-day Central Park.

This mosaic dedicated to John Lennon was tended for years by a Beatles super-fan.