Originally named Mukuntuweap, this hidden gem of a national park sits in the southwest corner of Utah on 229 square miles of vista-saturated land. Situated at the intersection of the Colorado Plateau, Great Basin, and Mojave Desert ecosystems, the park includes a swath of unique and astoundingly gorgeous geographies. Perhaps the best part of the park, though, is the fact that it's positively chock full of adventure and activities: From the vertigo-inducing heights of Angel's Landing (quite possibly the most dangerous hike in any of the nation's parks) to the almost unbelievably quiet slot canyons, there's something for everyone.

Zion National Park

Known as the "Crown of the Continent," Glacier is an enormous national park with over one-million acres, 130 named lakes, hundreds of species of animals, and more than 1,000 species of plant life. What's more, Glacier is the only American National Park to span two countries; it is an international peace park (the first of its kind back in 1932) with its natural wonders open to both Canadian and U.S. citizens. Unfortunately, the parks eponymous ice-shelves are rapidly-retreating and of the 150 glaciers present when the park was founded, only 37 remain. The rest are expected to vanish entirely within the next twenty years, so a visit to Glacier should be near the top of your to-do list.

Glacier National Park

The only national park south of the equator (and with an average of 3,000 visitors per year, one of the least visited), American Samoa spans an archipelago of three islands in the Pacific Ocean: Tutuila, Ofu-Olosega and Ta'ū. Of the park's 10,500 acres, over two-thirds is made up of water and its primary purpose is the preservation of the surrounding coral reefs, which contain over 200 species of coral and upwards of 900 species of fish including sea turtles and humpback whales. Objectivity aside, though, American Samoa is simply a beautiful park and one that consists of a truly unique ecosystem for an American park.

National Park of American Samoa

Well known for its enormous network of geothermal phenomena, Yellowstone was the first national park, established by President Ulysses S. Grant in 1872. Even though Old Faithful and the other geysers and springs get most of the attention, the diverse flora and fauna are the true stars of this park. In fact, Yellowstone is considered the finest "megafauna" environment in the lower-48 states, housing over 60 unique species of mammals and an untold number of birds and fish. Yellowstone is, quite simply, the park most representative of America's wild, and its legacy is one that won't soon be forgotten.

Yellowstone National Park

Perhaps the most iconic geographic formation in all of North America, the Grand Canyon spans the entire state of Arizona. In fact, the north and south rims of the canyon are not connected by road, save for the Navajo Bridge located at the southernmost tip of the state. The canyon is truly one of the natural wonders of the world and provides a plentiful bounty of outdoor activities (including some of the nation's best hiking and white-water rafting), as well as some of the most striking vistas in all of America.

Grand Canyon National Park

Named a National Park in 2003, Congaree is the second-most recently designated park in the nation. It is the product of a grassroots preservation movement started by the Sierra Club in 1969, which decried the destruction of the hardwood, old-growth forests of the American South. It's difficult to decide between the words "surreal" and "alien" to describe the forest's densely tangled, mossy, swamp-like atmosphere, but two things are certain: the Sierra Club's push for National Park status was the right move, and this national treasure is something that must be seen to be believed.

Congaree National Park

This park's centerpiece is Mount McKinley - the tallest mountain in North America. Indeed, the park's name comes from the mountain's indigenous name "Denali," which means "the high one." Of course, the mountain, however impressive it may be, is not the sole attraction of the park, which includes a unique, glaciated ecosystem that slows the metabolism of the various fish that inhabit its rivers, causing them to mature in a way seen nowhere else in the world. In addition to the obvious mountain climbing, the park plays host to more traditional camping as well as dog-sledding excursions.

Denali National Park & Preserve

Located near the Four Corners, this cluster of Anasazi cliff dwellings, which date back to the twelfth century, makes up one of the most important archeological sites in all of America. More importantly for this list, though, Mesa Verde perfectly illustrates the purpose and need for the National Park system. All through the 19th century, the Cliff Palace and Spruce Tree House sites were plagued with vandalism, both looting and wonton destruction. It was only with the site's designation as a National Park in 1908 that enough security was put in place to quell the damage. Fortunately, what remains is still a beautiful and powerful heritage site, and one that offers an unprecedented amount of access and hands-on learning.

Mesa Verde National Park

Part of the beautiful Blue Ridge Mountain Range (itself part of the Appalachian chain), the Great Smoky Mountains National Park contains the former homeland of the Cherokee Indians. It's a site representative of the strife between indigenous Native Americans and the encroaching American populations of the 19th century. As such, this park is uniquely focused on both historical importance and geographical beauty, and it's all the more powerful for it. Of course, with it's titular fog, spectacular hiking, and blue sunrises, it's also a truly gorgeous park.

Great Smoky Mountains National Park

Best known for its iconic "Delicate Arch," this park is actually home to over 2,000 sandstone arches, natural formations the likes of which exist nowhere else in the world. This doesn't even begin to count the other unique sandstone outcroppings such as the Fiery Furnace, the Parade of Elephants, and "slickrock" petrified sand dunes. Though it often unjustifiably overshadows its neighboring Southern Utah park Zion, Arches is spectacular in its own right. Plus, it's located just outside of Moab, a great city to visit.

Arches National Park

Located at the northernmost tip of the Florida Keys, Biscayne is a truly forward-looking National Park. Its sole aim is to preserve the marine habitat on which it stands; the park is made up of only 5 percent land, and of that land, half is actually petrified coral reef. Even with this preservationist bent, Biscayne still manages to captivate and entertain its approximately 500,000 yearly visitors with some of the best scuba diving in North America as well as kayaking, snorkeling, and other aquatic pursuits.

Biscayne National Park

Redwood National Park covers 37 miles of beautiful undeveloped coastline and nearly 40,000 acres of almost ethereally foggy Redwood forest in Northern California. Much like Colorado's Mesa Verde, Redwood National Park was created in response to the destruction of a national treasure, though the culprit here was logging, not vandalism. Indeed, by the time the park was established in 1968, nearly 90 percent of the forest had been logged. Luckily, under the protection of the National Parks Service, the coastal forest has grown back to its former glory and, in the process, a number of endangered species have regained their habitats. Hiking through Redwood Forest on a foggy summer morning should be on everyone's list.

Redwood National and State Parks

A park unlike any other on this list, Kentucky's Mammoth Cave system lives up to its name; in fact, its 367 miles of passageways make it the single largest cave system in the world. The cave itself is a world of wonders that includes all of the natural phenomena found in its above-ground brethren (rivers, lakes, canyons, springs, and "mountains") and some that can be found nowhere else (stalactites, "towers," and seven species of bats with a total population of over 10 million). In many ways, Mammoth is the perfect example of how unique and important each National Park is.

Mammoth Cave National Park