Mercer County is in Western Illinois. Of the 102 counties in the Land of Lincoln, Mercer County ranks 44th in terms of size (568 square miles). There is almost 1,000 acres of residential land and property for sale in Illinois's Mercer County based on recent Land Network data. The combined market value of land and rural real estate for sale here is almost $2 million. The average price of residential acreage for sale in Mercer County was $349,060. Browse all residential land and rural property for sale in Illinois to find residential land and properties that suit your lifestyle needs, from existing residential homes and estates to land ready for future residential-property development.