Fort Monmouth is a former installation of the Department of the Army in Monmouth County, New Jersey. The post is surrounded by the communities of Eatontown, Tinton Falls and Oceanport, New Jersey, and is located about 5 miles from the Atlantic Ocean. The post covers nearly 1,126 acres (4.56 km2) of land, from the Shrewsbury River on the east, to Route 35 on the west; this area is referred to as 'Main Post'.