A drive through the Evergreen State will bless you with incredible views of lofty mountains and ancient trees. But have you ever stopped to think what's under the ground? There are some spectacular caves in Washington state that are waiting to be explored. Like this 500-million-year-old, illuminated cavern that's 2,072 feet long!\nThe Gardner Cave is an underworld adventure located in Crawford State Park, that's nestled near the U.S.-Canada and Washington-Idaho borders.\nYou'll need a $10/day Discovery Pass to enter this park. And it's open from May to September, making it a perfect way to cool off in the summer.\nThe walls and ceilings of this geological wonder are decorated with icicle-like stalactites, stalagmites, flowstones and rimstone pools that were formed millions of years ago when shells of sea creatures formed into the limestone you see today.\nIt's also home to a 7.8-ton column, the largest one in all of Pacific Northwest.\nBeing one of the few "show" caverns in the state, it's pathways are completely illuminated with lights. Get flashlights to catch a closer glimpse of these wonders or join in on the 40-minute free tours.\nView this post on Instagram Gardner Cave was amazing #washingtonstate #crawfordstatepark #gardnercave #exploration #splunking #amazing #adventure A post shared by Kaylee Spangenberg (@kayrose93love) on Aug 5, 2018 at 6:31pm PDT\nThanks to curious humans, these formations have quirky names too: Fried Eggs, Soda Straws, Packrat Nest, Lopsided Wedding Cake, and Christmas Tree.\nThe story of how this spot was discovered is just as fascinating.\nA local bootlegger is said to have found this spot when the ground beneath him and his horse gave way. Thanks to the cave's chilly 39 degree-temperatures, he even stored his liquor here until he lost the lands in a game of poker!\nView this post on Instagram The largest limestone cave pillar in the Pacific Northwest, right here in Eastern Washington. Formed over thousands of years by the joining of a #stalactite and a #stalagmite. #gardnercave #easternwashington #explore #washington #selkirks #pendoreille #cave #spelunking #limestone A post shared by Backcountry Coconut (@jason_oshen_hershey) on Jul 29, 2016 at 9:22am PDT\nToday, you'll still have to descend a flight of stairs into a literal hole in the ground.\nAfter spelunking your way through, you can warm up at one of the first-come-first-serve, pretty picnic tables dotting this spot.\nThere are also several trails you can hit — the most popular one being a half-mile hike to the 49th Parallel, the international boundary between U.S.A and Canada!\nView this post on Instagram Cravin caving A post shared by Rachel Lunstroth (@rachel_lunstroth) on Nov 20, 2019 at 12:27pm PST\nThe Metalline Falls is a 20-minute drive away, and you can even go on a kayaking tour in the Boundary Dam.\nEither way, if you're craving for an adrenaline-packed day filled with caves, waterfalls and a canoe experience, we'd add this to our summer to-do lists ASAP.\nView this post on Instagram We hiked to Canada last weekend. I wonder what kind of adventures will come our way this weekend? 🤔 #pnwdogs #doberman #crawfordstatepark #gardnercave #boundarydam #metalinefalls #washington #pnw #adventurepup #dobermansofinstagram #hiking #pendoreille @dobermanmoms A post shared by Zor Blackwell (@zortheexplorer) on Oct 4, 2019 at 12:14pm PDT\nGardner Cave\nPrice: $10/day Discovery Pass\nHours: May through September, 9 a.m. to 6 p.m.\nLocation: 10381 Boundary Rd, Metaline Falls, WA\nWhy You Should Go: You can explore an ancient Washington cave that's illuminated throughout.\nWebsite\nWe strongly advise that before you go swimming or visit any location, you check the most recent updates on potential hazards, security, water quality, and closures. If you do plan to visit a location, respect the environment, and don't touch the cave's walls.