Much of what is known about the Adena culture comes from the artifacts and structures they left behind, including conical burial mounds of varying size and small circular earthen enclosures that likely served as ceremonial centers for several neighboring groups. Their artifacts were made from both local materials and materials brought from great distances, such as copper from the Great Lakes region. The Adena lived in small communities throughout southern Ohio and neighboring parts of Kentucky and West Virginia between 800 B.C.E. and 100 C.E., and they were both hunter-gatherers and farmers who grew crops like sunflowers and squash. Their culture gave rise to the Hopewell culture, which built enormous earthworks such as Newark's Great Circle and expanded its influence across much of eastern North America and beyond. In 1870, Infirmary Mound was large enough for Samuel Park, a former owner of the land, to climb for a commanding view of the surrounding landscape, but decades of plowing gradually reduced it until it can barely be made out today. It now stands about two to three feet high and seventy feet in diameter. No records show that anyone excavated it, so its builders cannot be identified with certainty, but comparison with similar regional mounds suggests it was most likely built as a burial mound by the Adena culture more than 2000 years ago. Adena burial mounds were used multiple times and grew with each addition of remains; some people were buried in mounds while others were not, some were cremated while others were not, and some burial sites included artifacts such as copper bracelets, spear points, and funerary objects. These differences are thought to reflect individuals' stature in life. Because Infirmary Mound is an ancient burial mound, it is a sacred site for American Indians and should be treated with the respect due to any cemetery or church.