Mercer County is in Great Lakes & Wilds Pennsylvania. Of the 67 counties in the Keystone State, 436,867-acre Mercer County ranks 33rd by size. 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!