Adams County is a county in the U.S. state of Ohio. As of the 2010 census, the population was 28,550. Its county seat is West Union. The county is named after John Adams, the second President of the United States.GeographyAccording to the U.S. Census Bureau, the county has an area of, of which is land and (0.4%) is water. It includes many parks and preserves, including one of Ohio's greatest archeological wonders, the Serpent Mound at the Serpent Mound State Memorial in Locust Grove. Serpent Mound lends its name to the Serpent Mound crater, the eroded remnant of a huge ancient meteorite impact crater. Other areas of note include state parks and national forests like Edge of Appalachia, Shawnee State Park, Adams Lake Park and Robert H. Whipple State Nature Preserve.Adjacent countiesHighland County (north)Pike County (northeast)Scioto County (east)Lewis County, Kentucky (south)Mason County, Kentucky (southwest)Brown County (west)
