America's national parks have become a popular escape for millions of travelers. They bring a unique variety of gorgeous landscapes, various wildlife, adventure sports, and incredible scenery. No doubt you’ve heard of the Great Smoky Mountains, the Grand Canyon and Yosemite. They were among the most visited national parks in 2015.

But how many designated national parks have you been to? If the answer is none, you’re missing out on “America’s best idea.”

For every park where masses of tourists frustrate you and prevent you from reconnecting with Mother Nature, there’s a magnificent piece of land someplace else that’s wonderfully wild and uninhabited.

Check out a few of some of America's lesser known, but stunning, national parks.

1. Katmai National Park and Preservation, Alaska

Did you know that Katmai is home to the world’s largest protected population of brown bears? Most people head to Denali for amazing wildlife and rugged wilderness. Escape the crowds at Katmai. The massive predators are spread out along the coastal areas most of the year. The most popular destination is definitely the Brooks Camp: It offers bear viewing, sport fishing, scenery, and rich history. Katmai is a remote fly-in-only park. It remains an active volcanic landscape and it's wide open for exploration.

2. Lassen Volcanic National Park, California

Lassen National Park is one of few locations on Earth where you can see all four types of volcanoes – plug dome, shield, cinder and cone. While Lassen Peak is the most famous, as well as the dominant feature in the park, there are numerous other-- literally-- hotspots to explore including mud pots, stinking fumaroles and hot springs. The park is also known for its nighttime activities in summer. Rangers lead starry night programs, and the Lassen Dark Sky Festival happens at the end of the season (Aug. 11-13).

3. Congaree National Park, South Carolina

Motorized transport is prohibited in the Congaree wilderness, which is known for its giant hardwoods and towering pines. You have to travel into the swamplands by foot or canoe, which only makes the experience more exciting. But this isn't suitable for everyone which is perhaps why the park has fewer visitors than others. Waters from the Congaree and Wateree Rivers sweep through a floodplain, creating wetlands, oxbow lakes and sloughs. The 22,200-acre park protects the largest contiguous tract of old-growth bottomland hardwood forest remaining in the U.S.

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4. Isle Royale National Park, Michigan

This was the least crowded national park in the country in 2015, with just 18,684 visitors-- but it's a secret gem for kayaking. It has many lakes, bays, and islands waiting to be explored. Isle Royale is the largest island in the largest fresh water lake in the world. The park is a rugged, isolated island, far from the sights and sounds of civilization, which is something many people prefer. You can even go scuba diving and explore the world’s most intact collection of shipwrecks.

5. Great Basin National Park, Nevada

In the shadow of Wheeler Peak, 5,000 year old bristlecone pine trees grow on rocky glacial moraines. People go to Great Basin for the solitude of the desert, the smell of sagebrush after a thunderstorm, the darkest of night skies, and the beauty of Lehman Caves. Far from a wasteland, the park is a diverse region with plenty to see. Great Basin is also is known for its easy access to excellent stargazing opportunities. Areas of high elevation and low light pollution make it one of the best spots to stare at the stars in the entire country.

Check out more of the country's coolest national parks.