Massachusetts Correctional Institution – Plymouth or MCI - Plymouth is a minimum-security prison facility located in the Myles Standish State Forest in Plymouth, Massachusetts. It is not to be confused with much larger Plymouth County Correctional Facility, also located in Plymouth, which has housed a number of celebrity inmates including Survivor winner Richard Hatch. Prison Mailing Address MCI-Plymouth Myles Standish Forest PO Box 207 South Carver, MA 02366 1952 establishments in Massachusetts Plymouth Buildings and structures in Plymouth, Massachusetts