The National Park Service (NPS) protects and preserves so many unique environments and landscapes, including caves. Jewel Cave National Monument in South Dakota is one such cave system within the NPS purview. At 220 mapped miles (354 km), Jewel Cave is considered one of the longest caves in the world and worth a visit for both exploration both above and below ground.

North-central Oregon is not only one of the most geologically interesting and beautiful parts of the state, but of the nation, really. A visit to John Day Fossil Beds National Monument is a great introduction to Oregon’s geology and interior landscape.

A geologic showcase that is a climber's gymnasium, plus two different desert settings, are on display in Joshua Tree National Park. Straddling the geographic divide that splits the Mojave Desert from an element of the Sonoran Desert, the park located about two hours east of Los Angeles in Southern California is both a day tripper's paradise and an adventurer's escape.

There’s more to Katmai National Park and Preserve in Alaska than just the bears and salmon this park protects and preserves. There’s active volcanics of Novarupta and Valley of Ten Thousand Smokes, the sport fishing, the 9,000 years of human history, and the sheer wildness of the landscape and location.

Lake Clark National Park and Preserve in Alaska is a dynamic national park, with movement as a constant force. From rugged, remote mountains, to active volcanoes, to glaciers, to wildlife, to the sockeye salmon industry, this is a national park and preserve attractive to photographers, backpackers, paddlers, birders, botanists, anglers, and hunters.

Fire and ice are two words that best describe the shaping of Lassen Volcanic National Park in California. Rebirth and resilience are two more words which should also be applied to this park.

Among the cave-centric park units within the National Park System, Mammoth Cave National Park in Kentucky stands out. Not only is this the longest known cave system in the world, but it’s a place rich in human history, both above and below ground, and home to some unique wildlife that call this cave home.

Eight centuries ago, for reasons still not fully understood, they got up and left. After roughly 700 years of living around and atop two slender mesas now recognized as part of southwestern Colorado, a society simply got up and left.

On a clear sunny day in the Seattle/Tacoma area of Washington State, the locals often remark “The Mountain is out.” Gaze eastward and you, too, will see The Mountain, a 14,410-foot-tall (4,392 m) volcano towering over the landscape in all its glacier-flanked glory. It’s a sight to behold. It’s also the centerpiece of Mount Rainier National Park.

Rugged mountains, wild forests, and glacially-fed rivers and streams have earned North Cascades National Park in Washington State the name “American Alps.” Protected alongside two national recreation areas (Ross Lake and Lake Chelan) bordering the park, this North Cascades National Park Complex offers visitors almost 700,000 acres of true wilderness experience.