Middlesex County is in North New Jersey. Of the 21 counties in the Garden State, Middlesex County ranks 13th in terms of size (322 square miles). The most common type of land for sale by combined acreage in Middlesex County is house. Browse all waterfront property for sale in Middlesex 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!