Power Plant and Dam No. 4 is a historic hydroelectric power generation station on the Potomac River, located near Shepherdstown on the county line between Berkeley and Jefferson County, West Virginia. The power plant is a tall one-story, limestone building on a high stone foundation. It is five bays long and has a gable roof. The building is built into a hillside, so the main floor is the top floor. The power plant was originally built by the Martinsburg Electric Company.
It was listed on the National Register of Historic Places in 1980.