Chestnut Hill is a village located six miles (9.7 km) west of downtown Boston, Massachusetts, United States. Like all Massachusetts villages, Chestnut Hill is not an incorporated municipal entity. It is located partially in Brookline in Norfolk County; partially in the city of Boston in Suffolk County, and partially in the city of Newton in Middlesex County. Chestnut Hill's borders are defined by the 02467 ZIP Code. The name refers to several small hills that overlook the 135-acre (546,000 m2) Chestnut Hill Reservoir rather than one particular hill. Chestnut Hill is best known as the home of Boston College and as part of the Boston Marathon route.
The boundary between Newton and Brighton was originally more or less straight northwest–southeast, following today's boundary at the east edge of the Newton Commonwealth Golf Course and the west boundary of the MBTA rail yards, following what is today St. Thomas More Road and Chestnut Hill Driveway through swamp land that is today the west edge of the Chestnut Hill Reservoir, and then rejoining today's city limit that runs essentially with the portion of Beacon St. that forms the west boundary of the Reservoir, and continues southeast to today's triple point between Boston, Brookline, and Newton near the intersection of Reservoir Road and Middlesex Road, Brookline.. Around the 1870s, the Lawrence farm land that is today bounded by Commonwealth Avenue, the slope dividing Boston College upper campus from lower campus, Beacon St., Chestnut Hill Driveway, and St.