The Wall of Philip Augustus is the oldest city wall of Paris (France) whose plan is accurately known. Partially integrated into buildings, more traces of it remain than of the later fortifications which were destroyed and replaced by the Grands Boulevards.
The wall was built during the struggles between Philip II of France and the Anglo-Norman House of Plantagenet. The French king, before leaving for the Third Crusade, ordered a stone wall to be built to protect the French capital in his absence.
At the time of its construction, eleven main gates were laid out. Four other main gates, as well as numerous posterns, were added to reflect the city's growth. The main gates were flanked with towers, and either vaulted or left open to the sky, with gabled roofs and portcullis.