The 68 mile Delaware and Raritan (D&R) Canal was built in the early 1830’s to serve as a transportation route between Philadelphia and New York. It is filled with 19th century bridges and bridge-tender houses, remnants of locks, cobblestone spillways and hand-built stone-arched culverts. The upper portion of the feeder canal follows the Delaware River through many historic towns. The main canal passes the Port Mercer bridge tender’s house, through the charming villages of Kingston and Griggstown to Blackwells Mills, ending up in New Brunswick. There are camping facilities available at the Bull’s Island The crushed stone and gravel rail trail passes through Hunterdon, Mercer, and Somerset counties in New Jersey. Trail End Points: Frenchtown, Trenton, and New Brunswick NJ. Park map.