You may not realize that the U.S. is filled with hidden, mysterious caves. Several are part of the national or state parks, and they're worth the excursion. Whether you are a thrill seeker looking for an adventurous exploration of a cave or you like the intimate, magical side, the United States has plenty to offer. Here are 10 of the most amazing caves in the U.S.
* Mammoth Cave National Park, Brownsville, Kentucky
Formed over 10 million years ago, with more than 400 miles of cave passage, Mammoth Cave is the longest known cave system in the world. Established as a national park in 1941, it was named after its size, not the woolly ancient animal. Above ground, you can camp, hike on the over 85 miles of trails and kayak on the Green and Nolin Rivers. Explore the caves by taking one of the several tours offered. You'll see amazing sights like the Star Chamber, which seems like you are looking at a starry night sky, not specks on the ceiling; Lovers Leap, which is lined with signatures of visitors from the past; and the famous Gothic Avenue, named for the formations that are similar to Gothic architecture.
* Wind Cave National Park, Hot Springs, South Dakota
Due to changes in the atmospheric pressure in and out of the cave, the caves tend to "breathe," or produce winds, hence the name of Wind Cave National Park. Filled with hundreds of passageways and rooms, some still being discovered, you'll be amazed by this underground wonder. For thrill seekers, there is the Wild Cave Tour, where you don hard hats and crawl through tight spaces. For the less adventurous, there is an array of less-strenuous tours available. (Please note, the Wild Cave Tour is not available in 2021.)
* Kartchner Caverns State Park, Benson, Arizona
Discovered less than 50 years ago, Kartchner Caverns was dedicated as a state park in 1999. It is home to one of the world's longest soda straw stalactites, measuring in at over 21 feet long, the world's most extensive formation of brushite moonmilk, plus the first reported occurrences of "turnip shields" and "birdsnest" needle quartz formations. Besides touring the caves, you can camp, hike and view wildlife. Kartchner also has been given an International Dark Sky Park Designation, meaning that there is minimal outdoor lighting to interfere with the view of the night sky, giving breathtaking views of the stars.
* Carlsbad Caverns, New Mexico
Perhaps the most well-known cave in the U.S., Carlsbad Caverns is home to more than 100 caves, with more believed to be discovered. The most recent room discovered was on Oct. 31, 2013, giving it the name "Halloween Hall." You will be amazed by chambers like the Big Room, which spans over eight acres, and is the largest readily accessible cave chamber in North America. There are spots of the caverns you can explore on your own, or you can take a ranger-guided tour, many of which require crawling. (Please note, ranger-guided tours are temporarily suspended due to COVID-19.)
* Black Chasm Cavern, Volcano, California
Declared a National Natural Landmark in 1976, Black Chasm Cavern abounds with helictites, formations found in only 5% of caves in the world and that seem to defy the laws of gravity with how they grow every which way. You can tour the caverns, as well as take a tour of the Miners Trail, dating back to the California Gold Rush during the 19th century.
* Ape Caves, Longview, Washington
Ape Caves in Washington is for those who want to explore on their own — there are no tours; they are simply part of a hike. The caves are actually lava tubes formed by an eruption of Mount St. Helens 2,000 years ago and are located within Mount St. Helens National Volcanic Monument and Gifford Pinchot National Forest. You can choose to hike the lower cave, which is less strenuous than the upper cave and gives you a chance to see a geographical anomaly, the "meatball," which, according to a local newspaper, is a "block of cooled lava which fell from the lava tube ceiling while lava was still flowing through the cave." The upper cave requires an 8-foot wall climb, narrow passageways and climbing over rock formations.
* Luray Caverns, Luray, Virginia
The largest caverns in the Eastern United States, the Luray Caverns have been dubbed "Geologies Hall of Fame" according to the official website. At this registered natural landmark, you'll be dazzled by sights like the Great Stalacpipe Organ, the world's largest musical instrument, which, according to the official website, "literally makes stalactites sing by gently tapping them throughout three acres of the caverns." It is played live during each tour, so you should get a chance to hear it if you go. You'll also be amazed by the mirror image of the stalactites given by Dream Lake, and Titania's Veil, which showcases calcite in its purest form.
* Moaning Caverns, Vallecito, California
Getting its name from the "moaning" sounds that the caves sometimes would emit (due to low water levels in holes in the rock), Moaning Caverns houses the largest single cave chamber in California. Although rare now, the moaning sounds were thought to have lured gold miners to the caverns in the 19th century, while MiWok Indian lore said it was a stone giant who lured people into the caves and, ultimately, to their deaths. Which might explain why several human remains have been found in the cavern, some dating back as far as 12,000 years ago. Their most popular tour, for visitors of any age, is the Spiral Tour, which leads you down a 100-foot-high, seven-spiral staircase. For the more adventurous (and those older than 12), there is the Expedition Tour, which requires hard hats, crawling and lots of wriggling.
* Lost Sea Caverns, Sweetwater, Tennessee
Listed by the Guinness Book of World Records as America's largest underground lake, the Lost Sea Caverns is a museum in and of itself: from an array of Native American artifacts found, bones of a Pleistocene jaguar from 20,000 years ago and dates etched in the rock by visitors from the past. Boat tours on glass-bottomed boats will take you to the lost sea after a tour of the caverns, part of the larger Craighead Caverns system. For groups of 12 or more, there is the option to experience the wild cave tour, where you not only get a more closeup look of the cave, but you can spend the night! You can also visit their general store, ice cream parlor, gem mine, glassblower and Cavern Kitchen cafe.
* Kazumura Cave, Hawaii
Hawaii has an abundance of caves, and Kazumura is its largest. At over 40 miles long, Kazumura is the longest lava tube in the world. Choose from three tours: Lava Falls (easy/moderate), Pit Room (moderate/challenging) and Maze, which is for experienced cavers and climbers only.