The United States is one of the most ecologically diverse countries in the world, with many mountains, alpine forests, arid deserts, beautiful beaches and incredible geological formations. Flip through this slideshow to find sixteen stunning national parks you might not have known existed, like the Indiana Dunes National Park, where an environment not unlike the sand dune beaches from Florida or South Carolina stretch along the state's border with Lake Michigan. Perhaps you'll find a few new parks to travel to this year. Who knows? They could be closer than you think.

For more information about any of these national parks, please visit NPS.gov.

West of Seward lies the Kenai Fjords National Park, where the Harding Icefield is located, surrounded by icy waters and lush forests. While there, attend a ranger-led day hike or lecture, kayak around the icefield, take a boat tour in search of whales and even hike the Harding Icefield Trail, a difficult 8.2-mile hike that promises the possibility of spotting a bear or two.

Near Holbrook, Arizona lies the large Petrified Forest National Park, where an ancient forest has been turned to stone after millennia of petrification. Whether by car, on foot or on horseback, you'll travel throughout geological history and discover some of the coolest desert landscapes in the country. The park's also great for geocaching and is pet-friendly.

Hot Springs, Arkansas is home to Hot Springs National Park, both equally known for its history and natural wonders. The park features nine historic bathhouses that drew travelers from across the country who had ailments such as arthritis, hoping the thermal baths would heal them. Take a dip in the hot springs after hiking through the park's lush forests, camp at the beautiful Gulpha Gorge Campground and take a peek at the springs' history at the Fordyce Bathhouse Museum and Visitor Center or on Bathhouse Row.

The Lassen Volcanic National Park in northern California, east of Redding. A beautiful alpine forest featuring Lassen Peak, the largest plug dome volcano in the world, the park is perfect for all types of outdoor activities, no matter the season. Hike around steaming fumaroles and swim or boat along the crystal clear Manzanita Lake. The park is also a great place for avid stargazers, with NASA doing frequent studies of the area.

Colorado's Great Sand Dunes National Park & Preserve is located in southern Colorado, a formation of large sand dunes that seem randomly placed throughout the alpine forests and the mountains beyond. Here, you can camp, hike and even go sand sledding! After a day of fun activities, kick back on the dunes and relax, stargazing at an official Dark Sky Park, where the stars shine even brighter.

Just outside of Miami lies Biscayne National Park, which preserves not only the lush mangrove forests and coral reefs that call the area home, but also 10,000 years of human history, ranging from Native American archeological sites to sunken shipwrecks. Boating, fishing, diving and kayaking are all activities to enjoy in this beautiful park. If you're not sure where to begin, consider going on a guided eco-adventure.

Haleakala National Park, located on Maui, is home to an ecosystem you might not think is located in Hawaii. Within bamboo forests lies a visibly barren landscape, shaped by its volanic past. Known for its importance to native Hawaiian culture, the land is known for rejuvenation. Visit the park early in the morning to catch a glimpse of a stunning sunrise over the island, then hike the Crater Trail to the Summit District, where you can spot birds native only to this one spot in the world and look out over a variety of summits. The Kipahulu District, on the other hand, is where you'll greet waterfalls, lush rainforests and beautiful beaches with reverence and awe, the native landscape much unchanged for thousands of years.

Ever wondered where the world's largest cave system is? It's located in Mammoth Cave National Park, Kentucky, which has earned its title of UNESCO World Heritage Site and International Biosphere Reserve. The forested park boasts over eighty miles of hiking trails to explore, as well as guided cave tours which will take you into a subterranean world few have experienced. The park also features three trails accessible for those in wheelchairs.

Located near Chesterton, Indiana on the shores of Lake Michigan lies Indiana Dunes National Park, a stretch of fifteen miles of sandy dunes and marsh that resemble a saltwater coastline more so than a freshwater coastline. The park hosts all your favorite activities, from geocaching to horseback riding to its own annual (and free) Outdoor Adventure Festival, which lasts for an entire weekend to help encourage people to explore the great outdoors.

Looking for a national park that offers true solitude? Like, island-in-the-middle-of-a-Great-Lake solitude? Isle Royale is a rugged, forested island surrounded by Lake Superior. Camping here and enjoying all of the fun outdoor activities, whether alone or with family or friends will offer opportunities to truly reconnect with nature and yourself. Go scuba diving, fishing or hiking while you're there. Perhaps you'll even catch a glimpse of the endangered wolves that inhabit the island?

Near International Falls, Minnesota lies the stunning Voyageurs National Park, a park filled with an intricated network of waterways and dotted by islands with conifers reaching to the sky. Part of the Northern Boreal Forest, the park offers a view of wild, unsullied nature, with beautiful trees and even more incredible wildlife. Another feature of Voyageurs National Park is the chance to see the Northern Lights during your trip.

Between Cleveland and Akron lies the Cuyahoga Valley National Park in Ohio. With over 125 miles of walking and hiking trails to explore, the park offers a sanctuary to humans and native flora and fauna alike. The parks features all-season activities, and even has golf!

Crater Lake National Park is located in Crater Lake, Oregon, in the Cascade Mountain Range. It formed from a volcano thousands of years ago when it erupted and then collapsed in on itself, forming the deepest lake in the United States, filled with clear sky-blue water. Take a self-guided hike through the Rim Village or drive through the Scenic Rim Drive to get incredible photos of the landscape and the lake, then head over to Cleetwood Cove for a boat tour or to swim during the summer.

The Guadalupe Mountains National Park, located near Pine Springs, Texas, is a mountainous area of desert landscape, filled with hardy flora and fauna. The area's stunning mountains will leave you breathless. It is also home to the world's largest Permian-era fossil reef, where, thousands of years ago, a large coral reef grew on the ocean floor in what is now a desert ecosystem. Today it is preserved for us to see at the park. Spend a night at the park to catch a glimpse of the Milky Way, and don't forget to check out the McDonald Observatory.

In the heart of red rock country in south-central Utah lies Capitol Reef National Park, a maze of gorgeous red rock cliff and canyon formations. It's home to the a wrinkle in the earth called the Waterpocket Fold, a geologic monocline that extends for almost 100 miles. Hiking in this park is rigorous and not for the faint of heart; the park is also perfect for avid rock climbers. For a more leisurely pace, check out the horseback riding or road tour options.

The country's newest national park is located in Glen Jean, West Virginia, in the New River Gorge. Home to one of the continent's oldest rivers, ironically named the New River, this green gorge offers much to be explored. Go whitewater rafting or canoeing along the river, or hike or bike on one of the many trails. A perfect photo-op is at the New River Gorge Bridge, the longest steel bridge in the Western Hemisphere and a true feat of engineering. Be aware, though, that you may not want to drive across it if you have a fear of heights.