The Adena culture was a prehistoric Native American culture that existed from around 1000 BCE to 200 CE, primarily in the Ohio River Valley. Known for their earthen mounds, the Adena people constructed burial mounds and ceremonial sites, which often contained artifacts like pottery, tools, and jewelry. These mounds reflect their complex social structure and spiritual beliefs. Adena society was characterized by a hunter-gatherer lifestyle, supplemented by early forms of agriculture. They engaged in trade with neighboring cultures, exchanging goods such as copper and shells. The Adena culture laid the groundwork for later cultures in the region, including the Hopewell culture.