The Delaware River Viaduct is a reinforced concrete railroad bridge across the Delaware River about 2 miles (3.2 km) south of the Delaware Water Gap that was built in 1908-10 as part of the Lackawanna Cut-Off rail line. It is the sister to the line's larger Paulinskill Viaduct. The Delaware River Viaduct also crosses Interstate 80 on the east (New Jersey) side of the river and Slateford Road and the Lackawanna Railroad's "Old Road" (now Delaware-Lackawanna) on the west (Pennsylvania) side.