Several bridges cross the Seyhan river within the city, the most notable among them is the Taşköprü, a 2nd-century Roman bridge. Currently used by pedestrians and cyclists, it was the oldest bridge in the world to be open to motorized vehicles until 2007. Demirköprü is a railway bridge that was built in 1912 as part of the Berlin-Baghdad Railway project. Regülatör bridge, at the southern section of the city, is a road bridge as well as a regulator for the river water. There are also three footbridges, Seyhan and Mustafakemalpaşa road bridges, the bridge of the metro and the bridge of the motorway spanning the river.