Mercer County is in Western Illinois. Of the 102 counties in the Land of Lincoln, Mercer County ranks 44th in terms of size (363,963 acres). The most common type of land for sale by combined acreage in Mercer County is residential property. Browse all waterfront property for sale in Mercer 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!