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Rock climbers and scramblers, this national park is your happy place. Around 8,000 rock climbing routes and 2,000 boulder problems are mapped out in Joshua Tree. And those formations are pretty historic—some have been around for 1.7 billion years, which is four times o

Katmai National Park is one of the best places in the world to spot a brown bear in the wild. Around 2,200 brown bears live within its boundaries, which isn't

Although no one's heard much from Lassen Peak for a century, there was around a year between 1914 and 1915 when it was a major hotspot for volcanic activity. During that time period, there were more than

Perched on the Mexico border, this Texas park is home to not just the tallest, but the four tallest peaks in the Lone Star State: Guadalupe Peak, a.k.a. "The Top of Texas" (8,751 feet), Bush Mountain (8,631 fee

It's not just fossilized logs laying around this park. There's a section of the Historic Route 66 that runs right through the heart of the Petrified Forest.

While you can drive through it, t

Sequoia National Park is fittingly home to the largest tree in the world (when measured by volume), and you can bet it has a name: General Sherman rises above the forest floor to reach 275 feet in height and is 36 feet in diamete

Theodore Roosevelt National Park is the only U.S. national park to be named after a person—and when you're at the park, you can even check out where the former president once lived. His three-room property, Maltese

he Sonoran Desert, in which the boundaries of this 143-square-mile national park fall, is the only place in the world where you can find the giant Sag

Mammoth Cave National Park is home to the longest cave system on the planet (at least that we know of). It stretches for 400-plus miles under 53,000 acres of forest and 70 miles of above-ground trails.

Alaska's Wrangell-St. Elias might not be one of the more famous national parks—it doesn't have the immediate recognition of, say, Yellowstone—but it's the largest one in the U.S. It spans ov