Located in rural Adams County, Ohio, the Serpent Mound is an effigy of a snake built into the earth. Believed to have been created around 1070 CE, the curving, grassy mound is about 1,330 feet (405 m) long and about 3 feet (1 m) high. Though scholars originally attributed the mound to the Adena culture, the effigy has more recently been dated to the time of the Fort Ancient culture. It is still unclear who built it, or why. What unusual event might have prompted the building of the mound? Discuss