Of 102 counties in the state, Hardin County ranks 101st by size (181 square miles). Hardin County is in Southern Illinois. There is around 1,000 acres of undeveloped land for sale in Hardin County, Illinois, based on recent Land Network data. The combined market value of farms, rural land, hunting land and other land for sale here is about $200,000. Browse all Hardin County undeveloped land for sale on the Land Network to find your next commercial property or land investment. The most common type of land for sale by combined acreage in Hardin County is hunting land.