When you think of America's national parks, your mind is automatically drawn to visions of the Grand Canyon or Redwood. While those are definitely some of the most iconic national parks in the United States, there are many others that aren’t quite as well known in states that might even surprise you. Here are four U.S. states that you might not have realized have a national park.

Kentucky

Waterfall at Mammoth Cave National Park
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While Kentucky might seem like an unlikely place for a national park, it actually has one of the most unique parks in the country. Mammoth Cave National Park is made up of 52,830 acres and was created to protect the largest known cave system in the world. That’s right, the largest cave in the world is in Kentucky.

The cave earned its name because of how mammoth it really is. Over 400 miles of the five-level cave system have been explored with much more left to be discovered. Visitors can take guided tours deep into the cave and experience all the wonders that lie beneath the ground.

South Carolina

Wooden path in the middle of cypress woods in Congaree National Park, South Carolina
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If you’re traveling through central South Carolina, and the trees keep getting taller and taller, you’re probably in Congaree National Park. The park consists of 24,180 acres of the oldest hardwood trees in the United States. They’re also some of the tallest trees on the entire East Coast.

The trees grow in a floodplain that floods about 10 times per year. Most of the time, the trees look like they grew straight up out of the water. Wildlife is abundant in the park and includes deer, birds, bobcats, and river otters. At night, park rangers lead owl-watching tours over the boardwalk. Visitors can enjoy the quiet peace of the forest by walking the boardwalk, fishing, boating, or camping.

Arkansas

Waterfall in Hot Springs National Park
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Arkansas has one national park, and it happens to the be the oldest one in the United States. Hot Springs National Park was established as Hot Springs Reservation in 1832, before the National Parks system even existed. It was created to protect the 47 thermal springs flowing from the nearby mountain.

Today, Hot Springs National Park is nicknamed “America’s Spa” and is known for its beautiful landscapes, pristine hiking trails and, of course, the hot springs. The water flowing out of the springs is 143 degrees Fahrenheit, so swimming is prohibited. You can, however, take some water with you in water bottles for drinking purposes. The water, in its natural state, is completely safe to drink.

For those who prefer a slightly stronger drink, Hot Springs National Park is the only national park to have a brewery! Superior Bathhouse Brewery actually uses the heated water from the hot springs to brew its beer. It’s the only brewery in the world to use thermal spring water in the brewing process.

Indiana

 Indiana Dunes National Park shoreline with lapping waves and clouds, Indiana
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On the shores of Lake Michigan, lies Indiana Dunes National Park. While Indiana may not be known for its beaches, this national park boasts more than 15 miles of pristine shoreline and over 70 miles of hiking trails that will impress even the most avid adventurers.

In addition to the ever-popular beaches, Indiana Dunes National Park also contains plenty of wildlife. Several marshes, wetlands and groves support all kinds of plant and animal life. While it may be one of the smaller national parks, it has the seventh highest biodiversity of any park in the United States. More than 1,000 plant species and 370 bird species call the park home. While a national park in Indiana might be surprising, it’s definitely no secret. The Indiana Dunes sees almost as many annual visitors as Mount Rushmore.