This national park is the only at-sea national park in the United States of America and is home to the historic Fort Jefferson. The park is located about 70 miles (112.65 kilometers) west of Key West and is accessible only by boat or chartered seaplane. The park and fort lure divers, snorkelers and nature lovers from all over the country who flock here to get a closer look at the highly-endangered staghorn coral, angelfish, rare birds and the loggerhead turtles that gave the island its name. Built in 1846, the five-sided fort covers more than 11 of the island's 16 acres (6.47 hectares). The fortress was never finished but when construction stopped, records showed that 16 million bricks had been used to build this monolith of a building. The park is also an integral component of the UNESCO-certified Everglades & Dry Tortugas Biosphere Reserve.

Established in 1940 over 571,790 acres (231,400 hectares) of land, this beautiful park is situated on one of the largest islands on Lake Superior. Isle Royale National Park is a great place to explore different varieties of flora and fauna, such as snowshoe hares, wolves, coyotes, and moose, which are intriguing subjects of study for scientists who conduct investigations of predator-prey relationships in this type of environment. The geology of the park is diverse, and it shelters everything from mixed broadleaf forests, boreal forests, and conifers to sugar maples and quaking aspens.

With a stretch of millions of acres of land featuring the tallest of peaks and the deepest of oceanic waters, Wrangell-St. Elias National Park and Preserve bears an astounding landscape quintessential to south-central Alaska. Summers seemingly go by in the blink of an eye, while winters make themselves at home at this park, the result of which is a frigid topography paving the way for an albescent wilderness. Cradling under the shadows of the snow-sheathed Wrangell Range, the sweeping terrains of the park are dissected by meandering, glacial rivers. Stippled across the park's expanse is an arsenal of rustic cabins, while a range of glaciers only adds to its frosty appeal. The park's pristine white expanse is enlivened by bursts of mosses and blueberries which lovingly co-exist with swathes of aspen, alder, willows, and spruce. The park's wintry terrains are traversed by a string of mammals including Arctic graylings, caribous, coyotes, beavers, Alaskan moose and wolves among others.

Cradled on the country's extreme northern frontiers, this national park features some of the most alluring silhouettes of nature. Tinged by the magnificence of the Brooks Range Mountains, the Gates of the Arctic National Park and Preserve is spread over a land of 8,472,506 acres (3428701.53 hectares). Lying above the Arctic Circle, the park comprises a sweeping topography that is punctuated with astounding, panoramic views. Inaccessible by road, it can be reached by air or by trails winding through the park's dense wilderness. Perhaps it is this almost-formidable, breathtaking tenor of the park that makes it all the more alluring. The park is dotted with stunning flora that is a feast for the eyes. It is also home to bears, moose, and wolves among other wild animals. With interweaving trails and a smattering of campsites, the Gates of the Arctic National Park and Preserve embodies nature at its rawest and wildest.

Located north of the Arctic Circle, Kobuk Valley National Park is a canvas of serenity and wild seclusion. One of the least-visited national parks in the United States, this park carries delightful intermingling of boreal and tundra forests. Long meandering rivers accentuate the landscape, known for its Great Kobuk Sand Dunes and the Caribou migration route. The park lies in the northern hemisphere, above the Arctic circle where vegetation blooms unhindered in the wake of long summers. Fringed by the Baird and Waring mountains, this entrancing park plays host to many activities like hiking and canoeing. Mottled with a tapestry of sand dunes, breeding grounds, and agile streams, this expansive national park bears the most diverse and unique semblances of nature.

Displaying remarkable geological diversity across its 1,630,889-hectare (4,030,015-acre) span, the Lake Clark National Park and Preserve is a stunning progression of spectacular snow-capped mountains, rainforests, glacial landscapes, and pristine coastlines. Christened after the largest lake in Alaska, Clark Lake, this park features a one-of-a-kind maze of complex ecosystems that shelter a wide variety of flora and fauna, including wildlife like grizzly bears and the Canadian lynx. The park provides excellent avenues for dark-sky viewing, its clear skies and unsullied air creating the perfect canvas for the Northern Lights. Touted as an exciting outdoor and wildlife destination, the park also offers incredible opportunities for hiking, kayaking and camping.

The expansive Katmai National Park and Preserve is regarded for its distinct Valley of Ten Thousand Smokes, grizzly bears and a dramatic volcanic landscape. Burrowed in Southern Alaska, the park was designated a National Monument in 1918. Salmon swim through meandering streams and brown bears sleepily voyage through the park's undulating terrains. A site favored by intrepid adventurers, this park is fringed by a tapestry of mighty mountains and hosts myriad activities like hiking, backpacking, back-country skiing and fishing, kayaking and boat tours. Among the large spectrum of wildlife residing here, gray wolves, weavers, porcupines, sea lions and sea otters also inhabit the park's diverse environments. With abundant natural features, this entrancing park is also home to a treasury of crater lakes and lava domes. The Katmai National Park is a historical and geological marvel par excellence.

Spread across 77,180 acres (31,234 hectares), the Great Basin National Park is an ecological haven. Established in 1986, the park has today become a center point of nature and adventure alike. Laced by a tapestry of soaring peaks and vegetation-covered mountains, this sprawling national park is shrouded in pristine allure which is framed by exuberant wilderness including entrancing thickets of sage, pine, aspen, juniper, and conifer. The sweeping topography of this park is cleaved by a tracery of winding trails, crystalline streams, and creeks, resembling a picture drawn straight out of a postcard. A canvas of vibrant beauty come spring, this sprawling national park is a sight to behold, with its interminable offering of aged trees, and rolling woods dotted with dainty campsites. Home to the famed Lehman Caves, the Great Basin National Park hosts an array of activities ranging from hiking, climbing, water sports, winter sports, camping and wildlife spotting among others.

The Congaree National Park is nature's stunning canvas replete with emerald expanses, babbling rivulets, and captivating animal life. Known to be one of the largest hardwood forests in the United States, the national park spans over 26,546 acres (10,742 hectares). It's a rich terrain, quenched by the confluence of rivers Congaree and Wateree, shaded with towering Point Loblolly Pines and lush American Elms. The verdant landscape is teeming with deer, dogs, armadillos, and otters while turtles, bowfins, and catfish revel in the waters making the place a delight for wildlife enthusiasts. The Cedar Creek which cuts through the park is a popular destination for canoeing and the winding trails beckon hikers all year around.

A remarkable destination located on the US-Canadian border, the Voyageurs National Park features a rich tapestry of lakes backdropped by distant boreal forests. A network of waterways featuring the Rainy, Kabetogama, Namakan and Sand Point lakes were established along the fur trade route that led to the Great Northwest', thus offering miles of unending shoreline under Aurora-lit skies. With its unmissable location on the Canadian Shield, the park is also stippled with a terrain of millennia-year-old rocks that still induce wonder. With spectacular offerings such as these, the national park is majorly known for its excellent recreational opportunities, from kayaking along its tranquil waters, to paddling to the shore's wondrous bounds.

Guadalupe Mountains National Park is the ideal place in Texas for nature-lovers to rough it and commune with Mother Earth. The park is home to some of the most stunning and unique natural landscapes in the country, including towering mountain peaks, deep canyons, and sweeping desert vistas. Activities include camping, hiking, plenty of wildlife viewing, and much more. It is also home to a number of historic sites, including the ruins of the Pinery Butterfield Stage Station and the Frijole Ranch, making it a delightful attraction for history buffs and adventure enthusiasts alike.

Riddled with undulating alpine landscapes which are dominated by country pathways and rumbling, snow-cloaked valleys, this teeming national park is a jewel of the North Cascades. Featuring sites enlisted on the National Register of Historic Places, the park sprawls across several acres, creating delightful patchworks of woodland and wilderness on its way. Fringed by a tracery of craggy hills, parklands and lush forested drapes, the park is interspersed by an array of crisscrossing rivers, lakes and ponds. The highlands and steep terrains of the park are lovingly adorned with carpets of Douglas fir, reed canary grass, bearberries and some other exotic plant species. A haven for intrepid mountaineers and hikers, North Cascades National Park is where species such as marmots, grizzly bears and wolverines lazily amble across mystical, wooded expanses.