Each stretching 550 feet long, the walls of the Octagon Earthworks form an enclosure large enough to contain four Roman Colosseums. It was built before the year 400 and points unmistakably to the position of the Moon at the peak of its 18.6-year cycle. This rare phenomenon is known as a major lunar standstill, and it’s happening right now. The current standstill began in the summer of 2024 and will last two years before embarking on another lengthy cycle.

The significance and sophistication of the Octagon Earthworks has been compared to that of Stonehenge and the pyramids in Giza. Despite that, the 2,000-year-old site was leased to a country club and used as a golf course for more than 100 years—up until January 1, 2025. After more than a decade of negotiating, the Ohio History Connection (OHC) took over the lease and opened the sacred landmark to the public.

The Octagon is one of an estimated 10,000 Native American mounds once scattered across central Ohio, ranging from burial sites to effigy mounds shaped like animals and other figures. Ohio is home to the world’s largest effigy mound, the Serpent Mound, snaking more than 1,300 feet across 60 acres, just east of Cincinnati.

“This was one of many epicenters of Indigenous population 500 years ago, and it’s not anymore,” says Dr. John Low, director of the Newark Earthworks Center at Ohio State University and a member of the Pokagon Band of Potawatomi Indians. At the start of the 1800s, there were more than 40 tribes in what is now Ohio, including the Shawnee, Kickapoo, and Miami. By 1842, they had all been forcibly removed under the Indian Removal Act.

Low says that although Indigenous peoples remained in other states like Michigan, Wisconsin, and Minnesota—each still home to 11 to 12 federally recognized tribes today—Ohio’s agricultural potential motivated Europeans of the 19th century to seize every last bit of tribal land. Now, there are no federally recognized tribes in the state. Despite visible markers of long-ago Indigenous cultures, Ohio’s Native American community is one of the smallest in the country, just 1 percent of the state population. Only about 2,000 mounds of the original 10,000 are still standing.

Still, Indigenous Ohioans like those behind the Cincinnati-based Urban Native Collective are leading a momentous charge to save what’s left of the state’s sacred sites. They say their efforts are less about “taking back” their land than preserving sites with “significant historical, spiritual, and archaeological importance”—not just for Indigenous people, but for everyone.

Years before the Octagon opened, the Urban Native Collective participated in a grassroots effort to buy and open Fortified Hill, the only earthwork that hasn’t been destroyed of six that were once found along the Great Miami River. It was tied up in a local dermatologist’s private estate until 2019, when the doctor died and the site went to auction. The preservationists purchased Fortified Hill* for $1.5 million, and it’s now open to the public as part of the Pyramid Hill Sculpture Park.

Even though the mound and many others across Ohio are overseen by organizations primarily led by white people, Low says it’s still a win just to free them from the constraints of private ownership. “Access is important for everybody,” he says. Even if people are visiting just to walk their dogs, “it is whatever you want the space to be.” Low says he learned from elders that ancestral land “is not sacred because of what we do or who we are, it’s sacred because it’s sacred.” In addition to improving access, publicization raises awareness, and “elevated awareness helps protect historic places because of their popularity and recognition,” says Neil Thompson, OHC’s public relations manager. The Urban Native Collective notes it can even have positive legal implications.