Dr Barnes' $25 billion private collection of art and arboretum.

A rare view of a preserved Victorian science museum.

Where America's first doomsday cult awaited the end of the world.

The world's first aircraft factory has been hiding inside an automobile plant for almost 80 years.

This massive airship factory is so large that it has its own indoor weather.

Small, privately owned island divided between Michigan and Ohio with abandoned vacation homes and a derelict lighthouse.

Where beautiful signs live on forever.

Some Moscow residents once claimed the bizarre, contorted mass of metal on top of the building was used to manipulate minds.

Dr. Strangelove-esque tours reveal the inside a bunker once reserved for Stalin himself.

The “City of Stairs” sits high in the Andes, above the world’s largest underground copper mine.

A record-breaking pool that uses computers to turn ocean water into cleaner, private swimming water.

This Japanese-inspired labyrinth of hot springs is hidden in a Chilean forest.

This metal tower in the desert provides views of a handful of Nazca geoglyphs.

An unexpected desert oasis in South America.

A once popular resort—said to be the vacation spot of gangster Al Capone—now remains abandoned in the woods of Arizona.

The biggest solar telescope in the world helps reveal the secrets of our sun.

A pair of giant roadside arrows are all that remains of a former Route 66 trading post.

The wreckage of a deadly bomber plane crash can still be found near an Arizona peak.

This 40-room dwelling tucked within a cliff was built by the basin's prehistoric residents.

Don't blink or you'll miss it.

In a 345-million-year-old cave that's 200 feet underground, dinner awaits.

This golf ball–shaped former desert real estate office now houses a UFO museum.

Open since 1938, this diner has kept its fountain, malt machine, and all the gum that greasers left beneath its counter.

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