Hopewell Culture National Historical Park preserves major ceremonial earthworks and burial mounds built by Indigenous people of the Hopewell culture in the Scioto River valley near Chillicothe, Ohio, dating from about 200 BC to AD 500. Its surviving complexes, including Mound City Group, Seip Earthworks, Hopeton Earthworks, the Hopewell Mound Group, Spruce Hill Earthworks, and High Bank Works, show large geometric enclosures, mounds, and alignments linked to ceremonial life and astronomical knowledge. Though parts of this sacred landscape were damaged or lost, the park protects nationally significant evidence of sophisticated engineering, organized labor, and broad Hopewell beliefs and practices across eastern North America.