10 quirky natural phenomena in the U.S. to experience at least once

Yellowstone’s Old Faithful lives up to its name with near-clockwork precision. Of the nearly 500 geysers at Yellowstone, park rangers can predict the eruptions of just six, including Old Faithful. This legendary geyser shoots water up to 180 feet in the air, on average, every 92 minutes. Rangers can pinpoint the next eruption within a 10-minute window, making Old Faithful one of nature’s most reliable spectacles.

Time Out tip: Check the National Park Service website or the free NPS mobile app for the next eruption time. There’s even a live-stream webcam so you can watch the magic unfold from your couch.

Great Smoky Mountains National Park is home to a curious firefly species called Photinus carolinus. For a few dazzling nights in late May or early June, these incredible insects sync up their flashes, lighting up the forest in perfect harmony. Let’s just say, it’s pure magic. For the best seats in the house, make your way to Elkmont Campground near the Sugarlands Visitor Center.

Time Out tip: You’ll need to enter—and win—a random lottery at Recreation.gov to secure a vehicle reservation. The lottery usually opens in late April, so mark your calendars and cross your fingers.

The singing sands at Great Sand Dunes National Park are like nature's secret soundtrack. When air is squeezed through the sand grains, an eerie hum fills the air. This sound typically occurs during a storm, but you may catch it while sledding down a sand dune. The "singing" is more noticeable in cooler months when the sand is dry, usually in late fall and winter.

Time Out tip: Rent a sandboard or sand sled outside the park, then head to the Dunes Parking Lot near the visitor center. Hike up the 650-foot-tall High Dune, then keep your ears open as you sled down.

The bioluminescent waves in San Diego are a surreal natural spectacle. Thanks to tiny plankton called dinoflagellates, ocean waves glow electric blue when these small organisms get stirred up in the darkness. The effect is other-worldly, to say the least. The dazzling show can happen at any time, but you’re more likely to catch it from spring to early fall.

Time Out tip: Head to La Jolla Scripps Pier or Torrey Pines State Beach on an extra-dark night for your best chance at snagging a front-row seat for nature’s neon blue spectacle.

The curious rainbow swamps at First Landing State Park in Virginia are nothing short of enchanting. In the fall or early winter, after a good rain, decaying leaves in the cypress swamps release natural oils that swirl into vibrant, kaleidoscopic patterns across the water’s surface. For the best views, stroll the wooden boardwalk on the Bald Cypress Trail.

Time Out tip: Head out on a sunny morning when the sun’s rays can make those rainbow-like hues really pop on the surface of the freshwater swamp.

The northern lights are a bucket list item that’s worth every bit of the hype. One of the best spots to catch this celestial display of vibrant greens, purples, and pinks is from the solitude of Denali National Park in Alaska. While your best chances are between September and April, a few other factors come into play. You’ll need a dark, clear sky and a good aurora forecast.

Time Out tip: You can see the northern lights from just about anywhere at Denali National Park, but if you want to up your odds, book a guided northern lights tour for access to the best viewing spots.

Thor’s Well in Oregon is like something out of a fantasy novel. Imagine the ocean seemingly pouring into a bottomless pit. No wonder it’s referred to as the “drainpipe of the Pacific.” This natural sinkhole is at its most dramatic shortly before high tide, when you can watch the tide roll in and the waves surge into the well.

Time Out tip: Thor’s Well can be a bit elusive. Keep an eye out for a turnoff just south of the Cape Perpetua Visitor Center on Highway 101. Park in the large parking lot marked as Cook’s Chasm.

Fly Geyser is a six-foot-tall geothermal geyser that’s equal parts natural marvel and happy accident. This vibrantly-colored geyser is located at Fly Ranch, on a parcel of private land near the Black Rock Desert. The so-named Fly Geyser began taking shape in 1916 when locals attempted to drill a well. When they discovered the water was too hot, they let it be. Today, the constantly spouting geyser stuns with reds, greens, and yellows, thanks to minerals in the water.

Time Out tip: Fly Geyser is at its most brilliant in the early-morning or late-afternoon when the sunlight makes its colors pop. For an up-close look, book a guided tour with Friends of Black Rock.

The Firefall at Horsetail Falls is a jaw-dropping natural wonder. For a few weeks in February, this 2,130-foot-tall waterfall glows like molten lava as the setting sun hits it just right. This rare, minutes-long phenomenon can only happen when the sunlight aligns perfectly with the falls, making it a must-see event that draws crowds. The best viewing spot? El Capitan picnic area.

Time Out tip: The Firefall is so popular that you’ll need a vehicle reservation from Recreation.gov for the last three weekends of February. Mark your calendar–reservations open up on December 1.

The ice caves at Wisconsin’s Apostle Islands National Lakeshore are a stunning, frosty wonderland along the rugged coastline of Lake Superior. From January to March, the frozen sea caves reveal intricate ice formations and striking blue hues. Visit in the late afternoon, when the setting sun amplifies the colors of the ice and rocks.

Time Out tip: Visit the caves on a weekday, if possible. Weekends can be a bit of a madhouse, and you may need to park as far as two miles from the caves.