Linking Rabat and Salé to form an urban hub, the Hassan II Bridge and its associated access works relieve both cities historic sites and populations of atmospheric and sound pollution. The design respects the overwhelming horizontality of the built and natural environments, allowing Rabats 12th-century Hassan Tower to retain its vertical dominance of the skyline. The concrete supports, in subtly varying arced forms, are deliberately delicate and lace-like in appearance. Besides providing transport connections, the structure also offers an urban roof over the alluvial plain of the Bouregreg River, creating a protected public space for markets and leisure activities.