In the Eure department, Vernon has two castles implanted on either side of the Seine. In the town itself, the Château Royal and its Tour des Archives date from King Philippe Auguste (1180-1223). In Vernonnet, the four turrets of Fort des Tourelles stand almost in line with the old medieval bridge and the mill. The Vernonnet district, on the north bank, is more popular and less renowned than the other side of the Seine. Vernon indeed started developing on the south bank in the 10th century.