Douglas County is in Central Illinois. Of the 102 counties in the Prairie State, 417-square-mile Douglas County ranks 72nd by size. The total value of about 1,000 acres of residential land and property recently listed for sale in Illinois's Douglas County was almost $4 million. The average price of residential land for sale in Douglas County was $344,888. 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.