Brookline is a town in Norfolk County, Massachusetts, United States, which borders on the cities of Boston and Newton. According to the U.S. Census Bureau, Brookline has a total area of 6.8 square miles (17.7 Square Kilometer), of which, 6.8 square miles (17.6 Square Kilometer) of it is land and 0.04 square miles (0.1 Square Kilometer) of it (0.44%) is water. Brookline borders Newton (part of Middlesex County) to the west and Boston (part of Suffolk County) to the east, north, south, northwest, and southwest; it is therefore non-contiguous with any other part of Norfolk County. While Brookline shares similarities[which] with many Northeastern urban neighborhoods, such as Chestnut Hill, Philadelphia, Brookline is unique in that it is a separate town. Brookline became an exclave in 1873 when the neighboring town of West Roxbury was annexed by Boston (and left Norfolk County to join Suffolk County) and Brookline refused to be annexed by Boston after the Brookline-Boston annexation debate of 1873.