Located in Somerset County, Rocky Hill is a borough with a clearly defined local character. The borough is a small borough in southern Somerset County near Princeton and the Millstone River. Historic homes, quiet streets, open land, and access to the Delaware and Raritan Canal contribute to its village character. Route 518 and nearby Route 206 connect Rocky Hill with Princeton, Montgomery, Hillsborough, Hopewell, and the wider central New Jersey region. Somerset County lies in north-central New Jersey, where the Raritan valleys, Watchung ridges, suburban employment centers, historic towns, farms, and preserved land meet. Interstates 78 and 287, Route 22, and regional rail service connect the county with Newark, New York City, central New Jersey, and eastern Pennsylvania. The result is a community that retains its own identity while benefiting from the transportation, employment, and cultural resources of the larger county.