The world’s largest combined collection of U.S. and Russian aircraft got its start in a poultry building.

This Italianate Villa-style castle is pretty to look at, just keep off the private property.

See the motorcycles that launched the stuntman to fame and the gear that saved his life.

Stories of sightless fish and ghostly cowboys are only a fraction of the legends surrounding this Kansas sinkhole.

The Bucyrus-Erie model 1850B electric shovel, or "Big Brutus," the largest existing electric shovel in the world.

The first home of the doomed aviatrix Amelia Earhart.

The United States's largest hand-dug well is topped with a state-of-the-art museum.

Marking the spot where a conquistador gave up his search for the fabled Seven Cities of Gold.

Home to Hollywood history and a very special salt crystal.

One of the Eight Wonders of Kansas and the first official National Natural Monument these stark formations look like nature's Stonehenge.

Hidden in plain sight, this lush garden sits atop one of the most iconic buildings in São Paulo.

Museum precariously perched on a massive yellow pillar.

This natural wonder drops 16 stories straight down through rare flora and streaming waterfalls.

This angular brutalist playground turns playtime into modern art time.

This former maximum-security prison is creepy, sobering, and supposedly haunted.

An abandoned village that doubled as "The Hunger Games"' post-apocalyptic wasteland is up for grabs.

A vast collection of rare, historical, and vintage supercomputers.

A mysterious monument meant to be a guide into "an Age of Reason" was destroyed after an apparent bombing.

The remains of one of America's first radiation testing grounds still rest ominously in a Georgia forest.

Kentucky, Tennessee, and Virginia meet at this point in the Cumberland Gap.

The highest point in North Carolina and the United States east of the Mississippi River, Mount Mitchell is named after argumentative explorer Elisha Mitchell.

A rapidly disappearing authentic bit of the old south.

The oldest bridge in South Carolina may have been designed by the same man who created the Washington Monument.

The secret city built by the Manhattan Project.