54 Best Sights in USA

This Historic Entrance to Mammoth Cave provides the centerpiece of historic locations in the visitor center area, a singular point to which human beings have gravitated—and into which they have descended—for 5,000 years. It is easily found at the end of the Historic Entrance Trail.

Despite its unabashed commercialism (announced by its many somewhat-over-the-top, retro-style billboard advertisements), this roadside curiosity, set squarely on the Continental Divide, easily merits an hour of your time—the short trail from the 1930s trading post (now the gift shop) just off NM 53 affords unusual vistas of blackened lava fields and gnarled juniper and ponderosa stands. It's about a 20-minute moderately strenuous jaunt up to the 1,200-foot-diameter crater of Bandera Volcano, which last unleashed a torrent of lava 10,000 years ago. An even shorter walk leads to an old wooden staircase that descends 100 feet into the bowels of a collapsed lava tube, where the Ice Cave never rises above 31°F year-round and has a perpetual floor of blue-green ice. The ice remains year after year because of the combination of the air flow patterns in the lava tube and the insulating properties of the lava itself.

The caverns are a tranquil change of pace from theme-park action, offering guided walking tours of ancient limestone caves and their formations. Historians believe that Native Americans used the caves as shelter from harsh weather. The temperature inside is naturally at 52°F year-round, so bring a sweater. The caverns are not handicap accessible, and strollers are not allowed. There's a gift shop with gemstones and souvenirs, a petting barnyard, and a picnic area.

Jewel Cave's more than 200 miles of surveyed passages made it the third-longest cave in the world as of 2020, while exploration continued. But for tourists who aren't cavers, it's the rare crystalline formations that abound in the cave's passages—not the cave's size—that are the main draw. Take one of the paid, year-round, ranger-led tours, and you'll be rewarded with the sight of tiny crystal Christmas trees, hydromagnesite balloons, and delicate calcite deposits dubbed "cave popcorn." Plan to arrive early in the morning, because summertime tours fill up fast and start at prescheduled intervals. While you wait, scenic surface trails and exhibits in the visitor center can be explored for free.

Thanks to Hilo's abundant rainfall, this lava tube is lush with plant life. Concrete stairs lead down to the 2½-mile-long tube, which has no lighted areas. The ground is uneven and damp, so wear sturdy shoes, bring a flashlight, and explore as far as you dare to go. There are restrooms and a covered picnic table at the cave, and parking across the street. Heed all warning signs when entering the caves.

It's a walk of 145 sometimes slippery steps down a tunnel to Sunny Jim, the largest of the seven caves in La Jolla Cove and the only one reachable by land. This is a one-of-a-kind local attraction, and worth the time if you have a day or two to really enjoy La Jolla. The man-made tunnel took two years to dig, beginning in 1902; later, a shop was built at its entrance. Today the Cave Store, a throwback to that early shop, is still at the cave entrance and is the oldest running business in La Jolla. The shop sells jewelry, postcards, shells, and watercolors by local artists. All visitors are required to sign a safety waiver at the entrance. Sturdy shoes are recommended for the 15-minute self-guided tour. You can overstay your welcome by booking out the Airbnb above the Cave Store.

Subterranean lava flow formed this mile-long cave roughly 700,000 years ago. Once you descend into its boulder-strewn maw, the cave is spacious, with 40-foot ceilings, but claustrophobes take heed: about halfway through, the cave tapers to a 4-foot-high squeeze that can be a bit unnerving. A 40°F chill pervades the cave throughout the year so take warm clothing.

To reach the turnoff for the cave, go approximately 9 miles north of Flagstaff on U.S. 180, then turn west onto Forest Road (FR) 245. Turn left at the intersection of FR 171 and look for the sign to the cave. Note: these forest roads are closed from mid-November to March due to snow. The trip is approximately 45 minutes from Flagstaff. Although the cave is on Coconino National Forest Service property, there are no rangers on-site; the only thing here is an interpretive sign, so it's definitely something you tackle at your own risk. Pack a flashlight (or two).

The Lewis and Clark Caverns, Montana's oldest state park, hold some of the most beautiful underground landscapes in the nation. Two-hour tours lead through narrow passages and vaulted chambers past colorful, intriguingly varied limestone formations. The temperature stays in the 50s year-round; jackets and rubber-sole shoes are recommended. Note that the hike to the cavern entrance is mild. A campground sits at the lower end of the park. Around the holidays they run a special candlelit cave tour.

Across the highway from Haena Beach Park is Maniniholo Dry Cave, a place steeped in legends. You can walk for a few minutes through a 30-yard-long cave, which darkens and becomes more claustrophobic as you glide across its sandy floor, hearing the drips down the walls and wondering at its past. Legend has it that Maniniholo was the head fisherman of the Menehune—Kauai's quasi-mythical first inhabitants. After gathering too much food to carry, Maniniholo's men stored the excess under a cliff overnight. When he returned in the morning, the food had vanished, and he blamed the imps living in the cliff's cracks. He and his men dug into the cliff to find and destroy the imps, leaving behind the dry cave.

Lighthearted, well-informed guides lead 45-minute tours (208 steps down, 232 steps up) into caverns a prospector named Walter J. Mercer discovered in 1885. Millions of years in the making, the sheer, draperylike formations and aragonite crystals that resemble snowflakes are enthralling. Dress in layers (even in summer) and wear nonskid closed-toe shoes for this mildly strenuous adventure.

Thirty minutes north of downtown San Antonio, you can trek down 180 feet below the earth's surface for a half-mile walk through this beautiful, historic cavern system. Take the original Discovery Tour to explore the largest show cavern in Texas with its stalagmites, stalactites, flowstones, chandeliers, and soda-straw formations. The more adventurous (and physically fit) can take the Adventure Tour to get down and dirty (read: muddy) like a real spelunker. The Hidden Wonders tour explores new chambers discovered completely hidden underground including a natural ballroom (available for events), involving the biggest investment in the caverns' history. Listen to knowledgeable guides as they tell the story of this cavern's beauty accompanied by a sound and light show. The tour ends with the B.A.T. (Belt Assisted Transport), the only conveyor system ride out of a cavern in the world that transports visitors back up to the surface.  Caverns are cool with high humidity. Wear comfortable shoes with good traction. Trails can be wet, and climbing and descending stairs are involved. Tour prices can vary by date. Surface attractions include a four-level ropes course, seven zip rails, and climbing towers. Booking and buying ahead is recommended for cavern tours.

A less crowded alternative to Mammoth Cave, Onyx Cave has a variety of beautiful formations, including delicate crystalline draperies and rimstone pools. Stalactites, stalagmites, and other formations, including a 40-foot column, are highlights of this wet cave. There's a Native American burial ground, where the remains date from 680 BC. It also has a small gift shop on-site that sells rocks and fossils—you can even buy a bag of earth and pan for your own stones. Tours last 30 minutes.

Deep below the surface of South Bass Island, the limestone Perry’s Cave, with its underground lake, has been an island must-see for generations. More recently, a family fun park has been built around the subterranean grotto, and now visitors can easily while away an afternoon at the attraction. Activities include miniature golf, gemstone mining, laser tag, an antique-car display, a rock-climbing wall, and a maze. There’s also a butterfly aviary that houses 50 different species from around the world.

From the attractive log cabin–style main lodge, an easy trail leads to nine granite caves that formed some 50,000 years ago, during the last ice age. This family-friendly attraction begun in 1922 also contains a small petting zoo with a herd of adorable fallow deer.

Drive around the area and marvel at the desert vistas, or overnight at one of five pack-in/pack-out campsites. The main attraction, however, is Mitchell Caverns. Access to them is via 1.5-mile round-trip hike and a two-hour, ranger-led tour, during which you'll encounter stalactites, flowstone, stalagmites, and possibly cave-dwelling animals. (Book campsites or cavern tours at  www.reservecalifornia.com.)

Stalagmites, stalactites, flowstone, ribbons, columns, helictites, and the "Big Room" are all part of the worthwhile tour into this privately owned cave. In 1876, miners found the opening to the cave while digging a flume into the mountainside to carry water to the gold mines below. The cave was opened to the public in 1927, just before the carving of Mount Rushmore began. The attraction also features the Soaring Eagle Zipride, Rushmore Mountain Coaster, Wingwalker Challenge Course, and other theme-park-style activities.

Most of the park's caves lie within its hundreds of feet of limestone strata, but atop that limestone sits a layer of sandstone and shale. Sandstone caves can be found in this ridgetop layer, which often lead to greater limestone caverns farther down. In hope of making such a discovery, explorer Floyd Collins entered Sand Cave in 1925 … but never left. His entrapment, and attempted rescue, made headlines across the nation and caused a near-carnival of activity outside the cave entrance. That entrance is visible close at hand from the overlook at the end of Sand Cave Trail. A series of outdoor exhibit panels along the trail explain the historic events. Note: Sand Cave is closed to public entry.

In 1880 a sea captain rowed a small skiff into a fissure in a 300-foot-high sea cliff. Inside, he was startled to discover a 125-foot-high vaulted rock chamber inhabited by hundreds of massive sea lions—the largest bulls weighing 2,000 pounds or more. Now one of the coast's favorite, if quite touristy, attractions, the caves are reached by an elevator near the cliff-top ticket office and kitschy gift shop; viewing is from behind a wire fence. This is the only known hauling-out area and rookery for wild sea lions on the mainland in the Lower 48, and it's an awesome sight and sound when they're in the cave, typically only in fall and winter (in spring and summer the mammals usually stay on the rocky ledges outside the cave).

Discovered in the 1930s by a local goatherd, this cave is one of the most popular secondary sites in the park, about a 40-minute drive southwest of the visitor center (you'll follow a ranger in your own vehicle from the visitor center to get there). Both the hike to the cave mouth and the tour will take about half a day, but it's worth it to view the deep cavern darkness as it's penetrated only by flashlights and sometimes headlamps. From the Slaughter Canyon parking area, it takes about 45 minutes to make the steep ½-mile climb up a trail leading to the mouth of the cave. The cave consists primarily of a single corridor, 1,140 feet long, with numerous side passages.

Wear hiking shoes with ankle support, and carry plenty of water. No kids under 10. It's a great adventure if you're in shape and love caving. Tours are sometimes suspended due to staffing issues.

When conditions like tides and wave action are just so at this popular visitor attraction, the force of pounding surf being squeezed into a narrow slot of cliffside pink granite causes a boom that sounds like thunder and can send ocean spray up to 40 feet into the air—soaking observers standing nearby behind safety railings. Time your visit within an hour or two of high tide for the best chance to observe the phenomenon; at low tide, take the stairway down to a viewing platform for a peek at the water-carved walls of the tiny inlet. At the parking area on the opposite side of Ocean Drive, a gift shop where you can buy souvenirs as well as to-go snacks and drinks occupies a cottage-like structure that was the park's first "official" ranger station.

Soaring to 11,750 feet, Mount Timpanogos is the centerpiece of a wilderness area of the same name and towers over Timpanogos Cave National Monument along Highway 92 within American Fork Canyon. After a somewhat strenuous hike up the paved 1½-mile trail to the entrance, you can explore three caves connected by two man-made tunnels. Stalactites, stalagmites, and other formations make the three-hour round-trip hike and tour worth the effort. No refreshments are available on the trail or at the cave, and the cave temperature is 45°F throughout the year, so bring water and warm clothes. Although there's some lighting inside the caves, a flashlight will make your explorations more interesting; it will also come in handy if you're heading back down the trail after dusk. These popular tours often sell out; it's a good idea to book online in advance, especially on weekends.

In addition to intricate cave formations, the 1.25-mile tour of this subterranean world includes 210-foot Silver Falls, the tallest underground waterfall in the eastern United States. The well-lit caverns, including a massive one measuring more than 100 feet, are home to a seismic station used to detect earthquakes and rocket launches all over the world.

Part of the Yampah Spa and Salon, the hot springs vapor caves are a series of three underground, geothermal steam baths. Mineral-filled water from a natural hot spring runs about 125°F under the floors of one of the few known natural vapor caves in North America, creating steam temperatures of 110°F–112°F within the rock chambers, where there are marble benches for you to sit on while you inhale the steam. You can take a break in an adjacent cooling room or the upstairs solarium when you need it. Spa treatments are also available, including massages, body wraps, and private mineral baths. Reservations are required and visitors are limited to two hours.

Crystalline chambers, reflecting pools, and limestone fill these underground caverns, named in honor of Sioux holy man Sitting Bull. Check out mirrorlike Diamond Lake, the abundant dogtooth spar crystals, and the aboveground nature trail.