These 2,000-Year-Old Mounds Trace the Path of the Moon

Just outside of Ohio’s capital, a wall of earth rises five feet from the smooth ground in a perfect circle, 1,000 feet wide. Standing inside that ring of mounded terra firma today, you can see the Moon rise right where the walls break and an ancient passageway leads to an enormous octagonal arena. Thousands of years ago, the Native Americans who built it would have been standing in that very spot, watching the same celestial scene.

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.