Of 102 counties in the Prairie State, Marion County is 42nd in terms of its size (576 square miles). Marion County is in Southern Illinois. Recent listings of lakefront property for sale in Illinois's Marion County totals almost 1,000 acres and a combined market value of nearly $2 million. The most common type of land for sale by combined acreage in Marion County is residential property. Browse all waterfront property for sale in Marion County on the Land Network to find the marina, lakefront and other recreational property that meets your needs, from waterside land perfect as a retirement investment to existing residential waterfront land and property for hunting, fishing and other outdoor-recreation pursuits! The most common type of land for sale by combined acreage in Marion County is residential property.