Lake Carnegie is a reservoir that straddles the borders of the towns of Princeton, West Windsor, Plainsboro and South Brunswick in Mercer and Middlesex counties in central New Jersey. The lake was created by construction of a dam along the Millstone River, though the lower portion of the lake actually follows the valley of its largest tributary, the Stony Brook. The Delaware and Raritan Canal and its associated tow path are situated along the eastern shore of the lake. Noted businessman and philanthropist Andrew Carnegie donated money for the construction of the lake, which was donated to Princeton University. In 1990, the Lake Carnegie Historic District was listed on the National Register of Historic Places.

West Windsor is a township in Mercer County, in the U.S. state of New Jersey. Located at the cross-roads between the Delaware Valley region to the southwest and the Raritan Valley region to the northeast, the township is considered to be an outer-ring suburb of New York City in the New York metropolitan area, as defined by the United States Census Bureau. As of the 2020 United States census, the township's population was 29,518, its highest decennial count ever and an increase of 2,353 (+8.7%) from the 27,165 recorded at the 2010 census, which in turn reflected an increase of 5,258 (+24.0%) from the 21,907 counted in the 2000 census.