The Charles River Reservation is a state park and recreation area in Watertown, Massachusetts. It is a linear park that runs for seventeen miles along the Charles River. It also contains a US Historic District, the Charles River Basin Historic District, which is located between the Eliot Bridge and the Charles River Dam. It connects the campuses of Harvard, MIT, and the Boston University.

The Charles River Reservation features several attractions, including the Charles River Dam, John F. Kennedy Park, and the Charles River Basin and Esplanade. The dam was completed in 1978. It was an upgrade from the 1910 dam and an improved way for flood control. The basin and esplanade is quite a natural area, serving as habitat for hundreds of plant and animal life. It is also the historic portion of the park. The John F. Kennedy Park is a 5-acre memorial to the late president JFK.