19. Smoky Mountains, North Carolina/Tennessee

Smoky Mountains, North Carolina/Tennessee

Flickr: mikerhicks / Creative Commons

Flickr: gaensler / Creative Commons

Flickr: fkehren / Creative Commons

 A subrange of the Appalachian Mountains, the Smokies are a mountain range along the North Carolina–Tennessee border. It’s the most visited national park in the U.S., with 9 million-plus visitors per year.