Miamisburg Mound is one of the two largest conical mounds in eastern North America. It is a burial mound built by the people that archaeologists have called the Adena culture (800 B.C. to 100 A.D.). Adena was the name Governor Thomas Worthington called his estate in Chillicothe, Ohio. It was at that estate that the first mound of this group of prehistoric Native Americans was excavated in 1901.