Who needs headlamps? From a bioluminescent bay in Puerto Rico to a Japanese trail lined with glowing mushrooms, these ten hikes are at their best when it's dark out. Pack your camera (leave the flash at home) and prepare to be amazed.

Racetrack Playa, California

You’ve probably heard of the “sailing stones” of Death Valley National Park, which inexplicably crawl across the desert all on their own. Whatever the cause, there’s no denying that they make for a striking sight. The rocks, trailed by clean tracks over the scaly desert floor, look otherworldly under the night sky.

From the Grandstand parking area, located in the north end of the park, it’s only about a half mile out to the Racetrack. Be extra careful to keep track of your location at night: the area is wide open, but there are no designated paths.

Hachijo-jima Island, Japan

This volcanic island off the east coast of Japan is home to plenty of hiking trails, with a special feature for night owls: bioluminescent fungi. Hachijo-jima is home to seven different kinds of mushrooms here that light the trail with a green glow.

A 50-minute flight from Tokyo will get you to the island, where shuttle buses can take you to hiking trails. The best time to see fungi is during the rainy season, May to September.

Mosquito Bay, Puerto Rico

There are several bioluminescent bays to visit in Puerto Rico, but Mosquito Bay, on the small island of Vieques, is your brightest choice (it even earned a nod in the Guinness Book of World Records). Bioluminescent plankton in the water light up when they’re disturbed, giving the bay an ethereal glow that intensifies around passing boats and swimmers.

For the best view of the glow, hike Cayo de Tierra, a popular trail that ends at an overlook above the bay. If you want to get closer, East Wind Cats offers guided tours on the waters of the bay, where you can dip into the glowing waters yourself.

South Kaibab Trail, Arizona

No surprises here: the Grand Canyon offers some pretty dramatic stargazing. For the best views, take the South Kaibab Trail to Skeleton Point for a stunning 360-degree overlook of the canyon and the cosmos.

The hike from the Yaki Point trailhead to Skeleton Point is about three miles long. If you have extra time, head out before sunset and stop at the aptly named Ooh-Ahh Point along the way.

Mekong River, Thailand

At seemingly random intervals throughout the year, the Mekong River puts on an as-yet-unexplained (some say mythical) pyrotechnic show. If you’re lucky enough to be there at the right time, you’ll see a series of glowing fire orbs shoot from the river and straight up into the sky.

Prime fireball time is late October through early November, and again in May. The stretch of river where most sightings are reported is located in the Nong Khai province. Keep a couple of local trails on deck in case you strike out with the Mekong; One excellent choice is the Namtok Tham Fun, which leads to a waterfall in the rainy season.

Trona Pinnacles, California

Keep a lunar calendar handy when planning your trek to the Trona Pinnacles: these otherworldly formations are at their best during the full moon. Over 500 porous tufa spires sit on the dried-out Searles Lake basin, and they’re especially striking under a vast night sky. A bonus for sci-fi enthusiasts: the Pinnacles have made appearances in TV shows and films like Battlestar Galactica and Star Trek V: The Final Frontier.

The Trona Pinnacles are located about 170 miles northeast of Los Angeles, near the town of the same name. They’re a measly half-mile from the parking area, and visitors are allowed to camp nearby.

Newnes Glow Worm Tunnel, New South Wales, Australia

The iridescent strands hanging from the walls of the 600-meter-long abandoned Newnes railway tunnel aren’t Christmas lights or stalactites: they’re hundreds of bioluminescent larval flies, which glow blue to attract the small insects they prey on.

If you don’t want to start early to walk the entire 14-mile railway line, drive through Newnes State Forest to the Glow Worm Tunnel parking area and follow the railway about two miles to the entrance of the tunnel. You may have to wade through a bit of water as you go, but you’ll be rewarded as the tunnel becomes pitch black for excellent glow worm visibility.

Galloway Forest Park, Scotland

Galloway, Europe’s only Dark Skies-recognized park, offers visitors naked-eye views of the Milky Way, as well as unparalleled views of shooting stars, the Andromeda galaxy, and the Aurora Borealis.

For serious stargazers, the Scottish Dark Sky Observatory on the edge of the park is open to the public. For a do-it-yourself experience, head to one of many approved lookouts, like Bruce’s Stone and Caldons Woodlands. If you’ve got your heart set on a Northern Lights sighting, January is the time to go.

NamibRand Nature Reserve, Namibia

This unfenced desert reserve been recognized by the International Dark Sky Association for its conservation efforts, which have yielded some of the darkest skies in the world. That means trekkers are in for some pretty unbeatable stargazing.

NamibRand is fairly remote, so plan on taking a couple of days to stay on the reserve. Night hiking options abound, but a popular choice is Tok Tokkie Trails.

Joshua Tree National Park, California

The namesake spikey trees of this park in California’s interior look beautiful, and a little eerie, under moonlight. Hiking after dark here is also a much cooler alternative if you’re taking on the desert in the broiling summer months.

You can’t go wrong most places in the park, but staying at least one night at a campground will give you the full experience. Bring binoculars, so you can see the Milky Way in all its glory.