Of 46 counties in the state, Barnwell County is 30th in terms of its size (557 square miles). Barnwell County is in Midlands South Carolina. There is about 1,000 acres of ranches for sale in Barnwell County, South Carolina, based on recent Land Network data. The combined market value of farmsand rural real estate for sale here is about $200,000. Browse all Barnwell County ranches for sale on the Land Network to find the ranch that's right for your business or commercial needs, from the sprawling legacy ranch to unbelievable residential ranch for your second home, investment property or retirement nest egg. The most common type of land for sale by combined acreage in Barnwell County is house.