On the prowl for the most unique roadside stops across America? Then buckle up and cruise on over to Lemmon — aka, the “cowboy capital” of South Dakota. There, right off U.S. Highway 12, you’ll find an otherworldly roadside oddity known as the Lemmon Petrified Wood Park & Museum. The peculiar park is the largest of its kind, taking up an entire block in the heart of the town’s downtown area. “It’s touted as the ‘Biggest Petrified Wood Park’ in the world which makes me wonder how many there are,” one past visitor wrote in a Tripadvisor review. “My guess is the Lemmon one is the only one and that it’s an inside joke. Go see it.”

This outdoor gem was the brainchild of a local amateur geologist named Ole Sever Quammen, Roadside America reports. As the park’s name suggests, it was created using thousands of tons of petrified wood, which is the fossilized remains of trees, as well as bits of boulders and dinosaur bones. “The petrified wood that was used in this park is just stunning,” another park-goer shared on Tripadvisor. “It all came from the fields surrounding the town and they put their creative genes to work. Plus, they have a display of rocks that have [dinosaur] claw marks in them. A very interesting park and worth a bit of your time to walk around.” 

Opened in the early 1930s, the park was eventually donated to the town in the 1950s, where it still stands for all to enjoy today. You can freely stroll the grounds throughout the year. However, the on-site museum and gift shop are only open in the summer from Memorial Day to Labor Day during the hours of 9 a.m. to 5 p.m.

Teeming with whimsy and wonder, this nook of the artsy, off-the-beaten-path town of Lemmon is definitely worth a visit if you’re in the area. Meander among the 100 or so unique petrified wood sculptures and other attractions scattered across the park. There’s certainly plenty to see, from a stunning waterfall fountain and wishing well to an imposing castle-like structure bedecked with dinosaur bones and lofty spires — some of which tower 20 feet above the ground. 

If you visit in season, be sure to check out the indoor exhibits, too. The Petrified Wood Park & Museum doesn’t charge an admission fee, at the time of writing, making it one of the best free museums in America for a family day trip. “This is a great place to learn about the history of the area,” reads a Tripadvisor review. “The docents in the museum and gift shop are gems! There is a playground and public restrooms on the adjacent block, making this a nice place to stop for a break on a long drive.” 

As if this place could get any cooler, you can even donate various artifacts and other historic relics to the park’s collection, though there’s no guarantee that your item will be put on display. If you want to take a gander at more dinosaur fossils, be sure to stop by the Grand River Museum before leaving town. It’s less than half a mile away and boasts an array of exhibits about the early ranching days, the history of Native peoples, and much more.