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Each year in the month of April, National Park Week promotes the natural beauty widely available across the entire expanse of the United States. To make the experience even better, weekend visits are often free during National Park Week, which might give you extra motivation to explore at least one of the more than 400 unique national parks scattered across the country.

Sequoia National Park

Most of Sequoia National Park is designated wilderness, accessible only by foot or on horseback. Located in the southern Sierra Nevada mountain range, the park contains five of the 10 largest trees in the world and boasts a range of elevations, from frigid alpine peaks to milder foothills.

Plus, there are more than just sequoia groves at the park. It's also home to hundreds of caves, including California's longest cave at more than 20 miles. The only one open to visitors is Crystal Cave, the park's second longest at more than 3.4 miles, filled with stunning, fragile marble formations.

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Joshua Tree National Park

Joshua Tree National Park spans nearly 800,000 acres in Southern California between two ecologically distinct deserts. Many birds, mammals, reptiles and insects depend on its twisted, spiky namesake for food and shelter. The nature trails and surreal rock formations make it a favorite destination for bird watchers, hikers, and rock climbers.

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Crater Lake National Park

America's deepest lake, which also happens to be one of the cleanest and most pristine bodies of water in the world, is the focal point of Crater Lake National Park in Oregon. It rests in the former summit of a dormant volcano that collapsed after a major eruption 7,700 years ago. One of the park's most fascinating volcanic features is a rocky island called Phantom Ship, which resembles a ghost ship from a distance.Hawai'i Volcanoes National Park

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Hawai’i Volcanoes National Park

Established in 1916, Hawai'i Volcanoes National Park features three active volcanoes:

·       Hualalai – which last erupted in 1801.

·       Mauna Loa – which last erupted in 1984.

·       Kīlauea – which is constantly erupting.

Within the park's 505 square miles, you’ll find landscapes ranging from fresh lava fields and lush rainforests to arid desert. Walk through a lush forest into the cave-like Thurston Lava Tube, where a river of red lava once flowed hundreds of years ago. The 600-foot-long tunnel, discovered in 1913, ranges in height from 10 feet to 30 feet – watch your head as you walk through.

Glacier National Park

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Glacier National Park is a glacier-carved wilderness in Montana's Rocky Mountains on the Canada-U.S. border. Often referred to as the crown of the continent, the park features more than 50 glaciers, 200 lakes and 700 miles of hiking trails. Bighorn sheep, grizzly bears and moose are often spotted here.

The vistas from the 50-mile Going-to-the-Sun Road are a photographer's dream. Crossing the continental divide at Logan Pass, this scenic drive offers waterfalls, glaciers and wildlife sightings. Take a guided tour in an iconic red bus, which are restored originals that have been operating since the 1930s.

Arches National Park

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The most widely recognized landmark in Utah’s Arches National Park is the 60-foot-tall, freestanding Delicate Arch, also depicted on state license plates and postage stamps. Over 2,000 natural sandstone arches like these are scattered throughout the park – more than anywhere else on the planet – in addition to a variety of unique geological resources and formations.

Take an easy drive on an 18-mile paved scenic road to visit all the major viewpoints and trailheads. Or, if you’re more daring, take a ranger-guided hike through the twisted labyrinth otherwise known as the Fiery Furnace.

Channel Islands National Park

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Five isolated, yet ecologically rich islands off the coast of southern California make up the off-the-beaten-path Channel Islands National Park. Of the eight Channel Islands, the five that make up the national park include Anacapa, Santa Cruz, Santa Rosa, San Miguel and Santa Barbara.

Created by tectonic forces five million years ago, these islands have always been separated from the mainland. With their tide pools, giant forests of sea kelp and 145 plants and animal species found nowhere else on earth, their nickname as ’California’s Galapagos’ is a fitting one. From scuba-diving and spearfishing to kayaking through sea caves and watching the migration of grey whales, there’s no shortage of recreational activities here.

Petrified Forest National Park

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Filled with the colorful petrified wood for which it is named, Arizona’s Petrified Forest National Park is in the heart of Navajo and Apache counties. The park is home to the Rainbow Forest Museum, featuring numerous fossils, paleontology exhibits and access points to hiking trails.

More than 600 archaeological sites have been found within the park’s borders. One of those archaeological sites is known as Newspaper Rock, which is home to more than 650 petroglyphs created by the ancestral Puebloan people. Other park highlights include the village of Puerco Pueblo where they once lived, and the Painted Desert Inn, a 1930s museum which features Hopi murals.

Hot Springs National Park

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The country’s smallest and oldest national park is not only packed with spa facilities but also considered a serious art destination. At Hot Springs National Park in Arkansas, 700,000 gallons of water flow each day from 47 springs into a complex reservoir system. The odorless water, at 143°F, is supplied to commercial baths as well as free fountains, to which visitors flock to fill their containers.

Spa-goers can enjoy the water’s healing properties at the 1912 Buckstaff Baths, the park’s only traditional thermal water bathhouse. But the park appeals to more than just bathers, also offering the Ozark Bathhouse, which has been converted into a fine art gallery.

Guadalupe Mountains National Park

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Rising more than 5,000 feet above the surrounding desert floor, the Guadalupe Mountains are known as ’the island in the desert’. Located east of El Paso, the Guadalupe Mountains National Park now protects the world's most extensive Permian fossil reef and three environmentally diverse ecosystems, including conifer forests, oak and maple woodlands and ancient limestone canyons.

There are no paved roads, but over 80 miles of developed trails provide opportunities for wilderness adventure, backcountry hiking and access to the highest point in Texas at 8,749 feet.

Are you ready for some outdoor fun during National Park Week? Don't forget to tag us in your adventure photos on Instagram. You can also find more inspiration for things to do in different states on our blog.