Oberbaum Bridge is a double-deck bridge over the River Spree and it connects the formerly divided districts of Kreuzberg and Friedrichshain. Traffic runs on the lower part and U-Bahn trains on the second level. It was built in 1895 on the site of a previous timber bridge built in 1724 when the construction of an elevated railway required a reinforced structure. The result was a seven-arched concrete bridge with a granite and brickwork facade. It is distinctive architecturally because of its mock medieval turrets - which recall the function of toll bridges and arches.