Thousands of years ago, Native Americans created earthworks larger than the Roman Colosseum in Ohio. Now their descendants are determined to protect them.

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.