McLeansboro is the county seat of Hamilton County, a mostly agricultural region comprising cornfields and small Midwestern farming communities. This often-overlooked area of southern Illinois is also home to a few surprising attractions, including the country's largest archaeological site,?Cahokia Mounds State Historic Site, over 100 wineries and outdoor recreation like bouldering and mountain biking in 280,000-acre Shawnee National Forest. Hamilton County is in Southern Illinois. Of the 102 counties in the Inland Empire, Hamilton County ranks 68th in terms of size (278,949 acres). The most common type of land for sale by combined acreage in Hamilton County is farms. Browse all Hamilton County undeveloped land for sale on the Land Network to find your next commercial property or land investment.