Of 102 counties in the state, Knox County ranks 23rd by size (719 square miles). Knox County is in Western Illinois. Illinois's Knox County has roughly 1,000 acres of lakefront land and property for sale based on recent Land Network data. The combined market value of land for sale here was about $7 million. Browse all waterfront property for sale in Knox 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 Knox County is undeveloped land.