An abandoned town is hidden in Great Smoky Mountains National Park.

This dramatic rail curve was once the target of a failed Nazi attack.

No one knows who painted this mysterious mural in a Penn State basement.

Journey through a collection of over 35,000 Halloween items from all generations.

Tour the luxe "glass cage" that inspired and unnerved the architecture world upon its debut.

This historic Illinois "Muffler Man" has been converted from axe-touting lumberjack to rocket-wielding space ace.

A mysterious light of unknown origin on the backroads of Missouri.

Outsider Art Community.

A Wild West jailhouse that slid down the mountainside.

Some of the tallest ancient American ruins continue to inspire awe and curiosity.

Pennsylvanian mass grave and possibly mass murder.

A local prank turned town icon.

Sail through this subterranean show cave that is home to a legend that would go on to name nearly everything around it.

When the Austin Dam failed it destroyed much of Austin...and then it failed again.

This extraordinary Depression-era expenditure was modeled after a postcard of a Mediterranean hotel.

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

These gardens recreate unique and endangered Michigan habitats.

This lone tree and dramatic sandstone outcropping are so beloved by Michiganders they can be found on one of the state’s coins.

Island where motor vehicles are banned -- home to the only carless highway in the United States.

Strange physical sensations and optical contradictions keep visitors coming back for more.

This secluded walking trail is a hidden gem of a Pittsburgh park.

One of the only memorials dedicated to journalists who died in combat.

This four-story steel sphere in Maryland was used to test biological weapons.

A tribute to a future time when gravity is conquered.