READ THIS NEXT: The 6 Best Off-The-Radar Destinations in the U.S. That Need to Be on Your Bucket List. Diablo Lake is located in the North Cascade mountains in northern Washington state. It’s reached via a roughly four-mile hike up to an elevation of 1,500 feet, though certain spots can also be accessed via car. “It sits between beautiful mountains and is a turquoise green color due to the glacial silt that runs into the lake,” says Chantelle Kincy, travel advisor and author of travel blog Flannels or FlipFlops. As the National Park Service (NPS) explains, rock particles called glacial flour “enter the lake when rock from the surrounding mountains is eroded by ice and flows into the water through glacial streams.” The floating glacial flour refracts sunlight, so the water takes on the most eye-catching color in the summer months. But it’s more than just Instagram-ready photo-ops—there are plenty of activities, too. “There’s a stunning overlook you can simply drive to, but there’s also swimming, kayaking, and plentiful hiking trails and campgrounds around the lake,” says Jessica Schmit of the travel website Uprooted Traveler. Do be aware that “because Diablo Lake is glacially fed, it’s cold year-round,” advises Kincy. As for hiking, choose between the 7.5-mile Diablo Lake Hike or the 3.5-mile Thunderknob Trail. The North Cascade mountains are about a two-hour drive northwest of Seattle, so if you’re looking for a longer trip, spend a few days in the city and then rent a car to head to the lake. Once you arrive, there are several places to camp out. Kincy suggests Colonial Creek North Campground, which is located right on the lake. At 1,943 feet, Oregon’s Crater Lake is the deepest lake in the United States and the ninth-deepest in the world. If those superlatives weren’t enough to entice you, it’s also beyond picturesque. The lake is situated within a caldera (a volcanic basin) formed 7,700 years ago when the 12,000-foot-high Mount Mazama collapsed after an eruption, says the NPS. “Other than rain and snow, the lake has no other water sources, making its famously blue waters incredibly clear and clean,” explains Schmit. In fact, “the water is so clear that objects can be seen up to 140 feet below the surface,” notes Matt James, founder of travel blog Visitingly. There are certain areas where swimming is permitted, but the water is typically very cold. Another unique aspect of Crater Lake is the series of small islands that formed during the volcanic eruption. According to the Department of the Interior (DOI), Wizard Island is the largest, rising more than 750 feet. In the summer, the NPS hosts a boat tour where guests can hike to the island’s summit. Other boat tours simply circumnavigate the caldera, though to reach all boats, you’ll have to walk down the mile-long Cleetwood Cove Trail. If hiking in any form isn’t your thing, a great way to see Crater Lake is by driving around the 33-mile Rim Road (do note that it is a narrow, winding road). It offers 30 scenic pullouts, according to the DOI, which include Pinnacles Overlook, where “visitors can see volcanic ash frozen into 100-foot-tall solid rock formations,” and Videa Falls, which “provides a view of a cascading waterfall and is one of the best places to observe some of the park’s plant life.” The drive is usually open from July to October since there’s a great deal of snowfall in the winter. Crater Lake is located within Crater Lake National Park in the Cascade Range of southern Oregon. On the western side of the range is Umpqua National Forest, an equally historic wilderness area that has plenty of campgrounds. READ THIS NEXT: 8 State Parks That Are Even Better Than National Parks, Experts Say. On the border of California and Nevada, Lake Tahoe is located within the Sierra Nevada Mountains. It’s the largest alpine lake (those at very high elevations) in North America, as well as the second deepest lake in the U.S. at over 1,600 feet, according to San Francisco-based company Extranomical Tours. It’s known as a popular vacation destination since it offers both ski and beach resorts. As James explains, the South Shore is where you’ll find most of the bustling dining and entertainment options, including hotels, casinos, and an active nightlife scene. “The West Shore is quieter and more rustic, with forests and meadows perfect for hiking, biking, and horseback riding. And the East Shore is the place to go for water sports, with Lake Tahoe’s only public marina,” he says. In the summer, James suggests Secret Cove or Sand Harbor if you’re looking for a quiet beach experience. The latter is where you’ll find those stunning rock formations; it’s also where the annual Lake Tahoe Shakespeare Festival is held each July and August. For a “more festive” atmosphere, he recommends Kings Beach or Tahoe City, both of which have cute downtowns and plenty of restaurants and hotels. In the winter, “the lake transforms into a winter wonderland,” says James. Palisades Tahoe (famous for its aerial tram) and Northstar California are two of his favorite ski resorts. Located in the Eastern Sierra Nevada Mountains, California’s Mono Lake is completely spectacular. It’s part of Mono Lake Tufa State Natural Reserve, which was created to protect the tufa towers, “calcium-carbonate spires and knobs formed by [the] interaction of freshwater springs and alkaline lake water,” according to the California Department of Parks and Recreation. These incredible structures were formed over the lake’s one million-year existence (it’s one of the oldest lakes in North America), with salts and minerals from the Eastern Sierra streams washing over. Because of its incredibly high salt content—nearly three times that of the ocean—Mono Lake is considered a saline soda lake. Taking a swim, therefore, is a truly unique experience since you’ll find it very easy to float. Though you’ll miss this in the winter, the cold weather is also a beautiful time to visit, as the tufa towers are capped in snow and reflect beautifully in the water. Bird and animal enthusiasts will find Mono Lake particularly exciting. James notes that it’s sometimes referred to as “America’s Serengeti” due to the diverse wildlife population. “The lake is also home to the world’s largest colony of alkali flies, and is an important stopover for migrating birds,” he explains. The Department of Parks and Recreation put the number of species of migratory birds at more than 80. Mono Lake is only a 20-minute drive west of Yosemite National Park, so it’s a perfect opportunity to see both of these natural wonders. Buckeye Hot Spring is a short drive north of Mono Lake, but if you head south, you’ll run into many hot springs, including Wild Willy’s, the Rock Tub, and Shepherd. For more travel advice delivered straight to your inbox, sign up for our daily newsletter. An hour-and-a-half north of Phoenix, Arizona’s Watson and Willow Lakes are surrounded by beautiful granite boulders. “These boulders provide a picturesque backdrop for those swimming, paddleboarding, and kayaking and create a natural playground perfect for climbing, hiking, rock climbing, and more,” says Brittany Sawyer, founder of the blog Travel by Brit. The rocks are formally known as Granite Dells. According to AZ Wonders, they formed 1.4 billion years ago and have been eroded over time “through a process called spheroidal weathering” to gain their unusual rounded shapes. The lakes are both reservoirs that were made in the early 1900s and then acquired by the local municipality to serve as recreation areas. If more adventurous activities aren’t your thing, the Prescott Peavine National Recreation Trail is a lovely way to see Watson Lake. Originally part of the Santa Fe Railway, it’s been converted to a six-mile walking trail. Both lakes are located in the town of Prescott, which is “known for its authentic cowboy history,” according to the city website, as well as Whiskey Row, a stretch of Gold Rush-era saloons that are now bars, restaurants, art galleries, and shops. Colorado’s Hanging Lake is in the middle of Glenwood Canyon in the White River National Forest, part of the Southern Rocky Mountains. According to the USDA Forest Service, it is a designated National Natural Landmark that “was formed by a geologic fault which caused the lake bed to drop away from the valley floor above.” Therefore, surrounding the lake are large waterfalls that cascade down through lush greenery. Hanging Lake is extra striking due to its emerald green waters, the result of its travertine bed that was “created by mineral deposits over thousands of years,” explains Mathew Bowley, marketing manager at European travel company Solmar Villas. To get there, you’ll have to take the 1.2-mile scenic trail that begins at the bottom of Glenwood Canyon, goes through Deadhorse Creek Canyon, and ends 1,000 feet up at Hanging Lake. The Forest Service cautions that it is “steep and rocky.” One important point is that you can’t swim in Hanging Lake since human interaction can damage the ecosystem and disrupt its limestone makeup. However, “a little detour on the route will take you to Spouting Rock,” says Bowley. “A cascade has been created by water sluicing through solid rock, cooling off hot trekkers below.” READ THIS NEXT: The 10 Best National Parks That Need to Be on Your Bucket List. Located in northwest Montana, the 30-mile-long Flathead Lake is the largest natural freshwater lake (by surface area), in the western U.S. and is considered one of the cleanest in the world, according to Montana Fish, Wildlife, and Parks (FWP). What’s interesting about Flathead Lake State Park is its “six units,” each one with its own unique terrain. Perhaps the most popular is Wild Horse Island, a 2,160-acre pine forest that is only accessible by boat. Here, you’ll see “bighorn sheep, mule deer, songbirds, waterfowl, bald eagles, and falcons, as well as five wild horses,” says Montana FWP.ae0fcc31ae342fd3a1346ebb1f342fcb As for the other units, Big Arm is a bay and beach perfect for relaxing, swimming, water skiing, scuba diving, and exploring the 2.5-mile hiking trail. Finley Point offers great Lake Trout and Lake Superior Whitefish fishing, as well as RV and boat camping sites. For more fishing, as well as boating and kayaking tours, head to the West Shore. This unit also provides incredible views of the surrounding Mission and Swan Mountain Ranges. Wayfarers is a forested park popular for its photogenic, rocky shoreline and the many wildflowers that cover the area from spring to fall. And, finally, Yellow Bay “is in the heart of the famous Montana sweet cherry orchards,” shares Montana FWP. Flathead Lake is less than an hour’s drive south of Glacier National Park, which is also full of wilderness and wildlife activities, so many travelers plan their trips around both attractions. The largest town near Flathead Lake is Big Fork, where, in the winter, you can participate in Montana’s famous dog sledding. We’d be remiss if we didn’t include a Great Lake on this list! Though they’re all pretty spectacular, Lake Superior is the largest freshwater lake in the world and contains 10 percent of the world’s surface freshwater. Surrounded by Michigan, Wisconsin, Minnesota, and Ontario, it’s so large that there is truly something for everyone. This includes snorkeling to see more than 300 shipwrecks, kayaking and paddleboarding, stargazing, and exploring more than 30 lighthouses, shares Pure Michigan. One of the most scenic parts of Lake Superior is Pictured Rocks National Lakeshore, a stretch of land along Michigan’s Upper Peninsula that’s made up of “towering cliffs, crashing waves, and colorful rock formations,” as James describes. A popular activity is to kayak through the rock caves, though the NPS does recommend that inexperienced kayakers choose to go on a guided tour. On land, Pictured Rocks has more than 100 miles of hiking trails. “And if you’re looking for a truly unique experience, you can even go ice climbing on the frozen waterfalls in the winter,” shares James. Another attraction on the lake is Isle Royale National Park, an 850-square-mile archipelago that’s accessible only by boat or float plane, according to the National Parks Foundation. They also note that “99% of the land mass is federally designated wilderness,” which includes “165 miles of scenic hiking trails and 36 campgrounds,” as well as wildlife like moose and wolves. Do note that the park is closed from November to mid-April. READ THIS NEXT: The 10 Best All-Inclusive Resorts in the U.S. for a Stress-Free Getaway. There are two main draws to Seneca Lake, the largest of the 11 glacial Finger Lakes. One, it’s supremely gorgeous and vast. “It measures an impressive 38 miles from north to south. With a maximum depth of just over 618 feet, it is one of the deepest wholly contained bodies of water in the country—for this reason, the U.S. Navy tests the sonars used on submarines from barges located on Seneca Lake,” explains Jeff Shipley, president and CEO of the Seneca County Chamber of Commerce. He also notes that the lake is highly accessible, “as boaters can make their way to the region from the Atlantic Ocean through a series of interconnected waterways and the Erie Canal system.” If you don’t have your own boat, there are several places for rentals or booking a boat tour. Stand-up paddleboarding, kayaking, and canoeing are also popular lake activities, according to the Finger Lakes Tourism Alliance. Carol Cain, principal and founder of local marketing company Brave World Media, recommends visiting the Finger Lakes National Forest on the lake’s east side. It’s “New York’s only national forest and home to countless wildlife, as well as wonderful hiking, camping, and swimming spots,” she says. Seneca Lake’s other selling point is that it’s in the heart of the Finger Lakes wine country. “More than half of the area’s wineries are located here, and its award-winning Seneca Lake Wine Trail helps host a variety of experiences that celebrate the diverse array of award-winning wineries,” says Cain. The wine trail covers 320 square miles around the Seneca Lake AVA (American Viticultural Area) and includes 27 cool-climate wineries. For more food and drink fun, Cain suggests hitting the charming small towns on the west side of the lake, as they have additional wineries and many restaurants “featuring the best of the region’s farm-to-table culture.” Caddo Lake State Park provides views unlike any other, with its famous cypress trees dripping in Spanish moss. The lake spans 26,810 acres, a “maze of bayous, sloughs, and ponds,” as Texas Parks and Wildlife (TPW) describes. Located on the border of Louisiana, it is the only natural lake in Texas and the largest cypress tree forest in the world, according to Haley Plotkin, founder of travel blog Ready Set Jet Set. Because of what’s lurking beneath the water, you can’t swim in Caddo Lake. “The lake is home to many rare and endangered species, including the American alligator, the American bald eagle, and the Louisiana black bear,” explains James. But you can canoe or kayak through the waters. There are 10 official paddling trails in Caddo Lake and the adjacent Big Cypress Bayou (a group of wetlands along the western edge of the lake). Plotkin says she highly recommends “a sunrise paddle for the prettiest photos.” Fishing is another popular activity at Caddo Lake, as it hosts more than 70 species of fish. And if you’re looking for somewhere to stay, TPW notes that there are 46 campsites, seven screened shelters, and 14 historic cabins.