The Cork Run Tunnel, also known as the Berry Street Tunnel, is one of nine tunnels built in Pittsburgh, Pennsylvania on the original Pittsburgh and Steubenville Railroad. The tunnel was built beginning in 1851 as a single-track bore 2,100 feet (640 m) long, approached by deep open cuts, to connect central Pittsburgh with points to the west, on the south side of the Ohio River. A shaft was sunk from the overlying ridge to a point near the midpoint of the tunnel to speed construction and to provide ventilation.