Marine Corps Base Quantico, also known as MCB Quantico, is a United States Marine Corps installation located near Triangle, Virginia, covering nearly 55,148 acres (86.169 sq mi) of southern Prince William County, Virginia, northern Stafford County, and southeastern Fauquier County.
Used primarily for training purposes, MCB Quantico is known as the "Crossroads of the Marine Corps".
Marine Corps Base Quantico is located 35 miles south of Washington, D.C., in Prince William County, Virginia. It can be reached from exits 148 (South Entrance) and 150-A (North Entrance, Main Gate), just off I-95.