The Marlborough Historic District is a cement factory located on James Road in Pleasant Plains Township, Michigan. It was designated a Michigan State Historic Site in 1971 and listed on the National Register of Historic Places in 1972.
The ruins of the Great Northern Portland Cement Company plant and the nearby town of Marlborough are spread over an 80-acre plot of land. Marlborough once contained 72 houses, an opera house, school and post office, and an 88-room hotel. none remain. The cement plant was constructed almost entirely using reinforced concrete; the storage warehouse was several hundred feet in length, and the plant held six kilns and fourteen grinding mills.