The Paulinskill Viaduct is a historic railway bridge located in New Jersey. Built in the late 19th century, it spans the Paulinskill River and was originally part of the Lackawanna Railroad. The viaduct is notable for its impressive stone arch design and is one of the largest of its kind in the United States. Today, the Paulinskill Viaduct is part of the Paulinskill Valley Trail, a recreational path that attracts hikers and cyclists. The structure is recognized for its historical significance and is listed on the National Register of Historic Places, making it an important landmark in the region.