America is a nation with a landscape as diverse as its citizens. It’s hard to imagine that you can find a desert, rainforest, endless acres of farmland, some of the world’s most beautiful beaches, and a few of the largest lakes on the globe all within the borders of one country. But the third largest country in the world boasts a staggering 58 national parks that give visitors a chance to enjoy the nation’s natural splendor. According to the National Park Service, there are five in particular that received the most foot traffic in 2018.

1. Great Smoky Mountains National Park: 11,421,200 visitors

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Usually, when you talk about national parks, people immediately look westward. And yes, some of the more iconic parks are west of the Mississippi River. But you might be surprised to realize that the most popular park by traffic is the Great Smoky Mountains National Park in the American South. The park sits on the Smoky Mountains ridgeline and straddles North Carolina and Tennessee. These mountains are part of the Appalachians—one of two major mountain ranges in the U.S., and they are often overshadowed by their bigger sibling, the Rocky Mountains.

Great Smoky Mountains National Park officially became a UNESCO World Heritage site in 1983 and earned the title of International Biosphere in 1988. This national park is more than 800 square miles and is home to over 19,000 documented species of plants, animals, fungi and other organisms. However, experts believe that an additional 80,000 to 100,000 species of undiscovered organisms live in this park.

2. Grand Canyon National Park: 6,380,495 visitors

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The Grand Canyon needs no introduction, as it's been a popular vacation destination for decades. Whether you were dragged on a family road trip like National Lampoon’s or took a helicopter ride for a breathtaking overhead view of the iconic canyon, you know that there’s more than one way to see this destination. Admitted into the national park system in 1919, the Grand Canyon was a personal favorite of President Theodore Roosevelt.

The park is divided into the North and South Rim. While the South Rim is open year -round, the North Rim is closed during the winter. Because of this, the South Rim is the more popular portion of the park. The actual canyon is a mile deep and typically 10 miles wide. But if you decide to drive around the canyon, it can take up to five hours to drive from the North Rim Village to the South Rim Village. Also, visitors should be aware that they might have trouble breathing since the canyon rises 7,000 to 8,000 feet above sea level, depending on the location.

3. Rocky Mountain National Park: 4,590,493 visitors

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Colorado is home to a number of beautiful national parks, but the most popular one is Rocky Mountain National Park. This particular park is home to Gray’s Peak, which is the highest point in the Continental Divide in North America. The Continental Divide is the most prominent watershed separation in the Americas. Depending on which side of this natural geological feature a river is located, its water will either flow into the Pacific or Atlantic Ocean.

Rocky Mountain National is one of the most diverse park landscapes. You can easily shift between three ecosystems, depending on your elevation. Begin with meadow valleys at the lowest heights (5,000 feet) to Evergreen forests in the mid-range (9,000 to 11,000 feet), and finish with the most challenging Alpine tundra above 11,000 feet.

4. Zion National Park: 4,320,033 visitors

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If you’re looking for an accessible park that’s ideal for travelers of all experience levels, you can’t go wrong with Zion National Park. Set in southwestern Utah, this park is a quick drive from Las Vegas, making it a great day trip if you’re not much of a gambler. Zion was Utah’s first national park, even though others like Bryce Canyon and Arches National Park tend to get more commercial attention.

This park is nestled between the Mojave Desert, the Great Basin, and the Rocky Mountains, so nature fans will enjoy a diverse array of flora and fauna. Zion is also home to ancestral Puebloans,  who created a site that is both diverse and sacred. History buffs should head to the Zion Human History Museum on the park grounds to learn more about the park’s history and its earliest inhabitants.

5. Yellowstone National Park: 4,115,000 visitors

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Home to the iconic Old Faithful geyser, Yellowstone National Park is the oldest park in the U.S. National Park System. The park has been greeting visitors since 1872, with its geothermal formations being its most popular attractions. You might be surprised to find that Yellowstone offers full access to park services and activities only in July and August when the summer season is most mild and welcoming to guests. The rest of the year, however, the park’s elevation creates unpredictable weather, which leads to partial closures in the interest of safety. Much like other parks, Yellowstone also has a rich ancestral history, with the Folsom people calling the region home 10,000 years ago.

So, now you know which U.S. national parks are the most popular with visitors. Which ones have you visited? Which parks do you think should be called the best national parks?