Discover the world-class, jaw-dropping sites that define our most stunning landscapes, from coasts to caves.
1 of 7Photo by Kenny Braun
Palo Duro Canyon
Wow Factor: At 120 miles long, 20 miles wide, and 800 feet deep, it's the second largest canyon in the U.S., with "painted" canyon walls and intricate formations.
You'll Love If: You dream of being in a Western.
Explore It: Take a horseback ride through the Prairie Dog Town Fork of the Red River to see Spanish Skirt formations and a view of Sad Monkey Peak, named for the shape of the peak's cap rock ($35). oldweststables.com
2 of 7Photo by David Muench/Corbis
Mammoth Cave National Park
Wow Factor: The longest cave system in the world, with 390 miles of interconnected passages and rooms, named for its massive underground cathedrals.
You'll Love If: You think head-lamps are cute.
Explore It: The Violet City Lantern tour re-creates the cave's original guided tours from the mid-1800s on a lantern-lit walk ($15). nps.gov/maca
3 of 7Photo by Robbie Caponetto
Everglades National Park
Wow Factor: This 1.5-million-acre "river of grass" is the largest mangrove ecosystem in the western hemisphere. It's been designated a World Heritage Site and an International Biosphere Reserve.
Wow Factor: Once called La Isla Blanca (White Island), this 113-mile skinny strip of pale-white sand is the longest undeveloped barrier island in the world.
You'll Love If: You prefer beaches sans miniature golf.
Explore It: Head south as the road transitions to sand to gather ark and coquina shells on your own "private" beach. nps.gov/pais
5 of 7Photo by Pat & Chuck Blackley/Alamy
Wow Factor: Cumberland Falls, aka the "Niagara of the South," creates a rare moonbow when its spray catches the light of a full moon.
You'll Love If: You always wondered about that pot of gold.
Explore It: Visit Cumberland Falls State Resort Park during the five-day window surrounding a full moon. Naked eyes may see only a faint arc, but cameras can capture the full color spectrum. visitcumberlandfalls.com
6 of 7Photo by Jeff Hunter/Getty Images
Wow Factor: The only living coral reef in the contiguous U.S., this shallow-water wilderness is one of the top snorkeling and diving destinations on the planet.
You'll Love If: Lying on a beach makes you ants
Explore It: A snorkeling tour ($45) takes you to Christ of the Abyss, a statue 25 feet underwater in Key Largo's John Pennekamp Coral Reef State Park. captainslate.com
7 of 7Photo by Art Meripol
Red River Gorge
Wow Factor: Our answer to Utah's Arches National Park, the gorge has 100-plus natural sandstone arches, the highest concentration east of the Mississippi.
You'll Love If: You marvel at sculptures in nature.
Explore It: A 1-mile-loop trail leads over and under Sky Bridge, a 76-foot-long stone arch that forms a bridge amid the treetops. www.fs.fed.us/r8/boone