Bridgewater Township is located in Somerset County, New Jersey. A relatively large (over 32 square miles) suburban area in the state’s picturesque Skylands Region, it borders 13 other municipalities. The northeastern portion of Bridgewater is where the first ridge of the Watchung Mountains passes through. The north branch of the Raritan River forms the township’s western border with Branchburg.
Bridgewater is made up of a number of communities and sections, one of which is the residential hamlet of Martinsville. With its own commercial center, its own post office and ZIP code.