The Ries Railway (German: Riesbahn) is the current name of the line between Aalen and Donauwörth via Nördlingen. The name is derived from the Nördlinger Ries depression, and the line is operated by Deutsche Bahn (DB). The line consists of a section of the Aalen–Nördlingen railway built by the Kingdom of Württemberg as the Rems Railway and a section of the Nördlingen–Donauwörth railway built as part of the Ludwig South-North Railway by the Kingdom of Bavaria, two of the oldest lines in Germany.