Rippling sand dunes frozen in the Arizona rock.

A self-built castle made by a mysterious man.

In the back of a nondescript sports bar is a museum-worthy mural by legendary cartoonists.

A herd of plastic cows hangs out under this transmission tower in rural Georgia.

The 72-foot giant escaped confinement in a large patch of mulch only to be reburied in the sandy shores of the Potomac River.

World's largest college campus includes a wildlife sanctuary and a former movie set on more than 28,000 acres.

One of the world's largest automobile junkyards is a unique landscape of metal and moss.

This mysterious twin turboprop Grumman G-159 covered in graffiti has spent a decade and a half abandoned.

This folk art compound was built by a fortune teller on the advice of three people from the future.

The remains of the iconic train crash from the movie The Fugitive can still be found rusting along the Great Smoky Railroad.

The rare American Civil War-era weapon was never fired in anger.

This 1830s store is believed to be the site of Harriet Tubman's first stand.

The elevator hidden in a smokestack on Roosevelt's yacht now serves as a monument to the former president.

Famous for its bio-luminescent inhabitants, known as "dismalites."

You'll need cowboy boots to trek to this old-fashioned saloon nestled in a giant natural cave.

148 feet long and in the middle of a verdant forest.

This maze-like slot canyon is a unique gem within an already fascinating geological area.

A delightful park featuring homemade scale replicas of dinosaurs, tucked away in the Tennessee mountains.

A cabin completely covered in coffee mugs, where visitors are welcome to leave one of their own—if they can find an empty nail.

An ever-evolving wall of graffiti art off East Liberty Street.

The city is full of whimsical portals to another world.

These gardens recreate unique and endangered Michigan habitats.

A three-story tower of books about Abraham Lincoln is one of the more unusual monuments to the president.

The walls of the iconic dome are hollow and have a secret stairway.