Model of the fortress built by Philip II in the 12th century, with remnants of this building still visible (medieval Louvre). Philippe Auguste's fortress of 1190 was not a royal residence but a sizable arsenal comprising a moated quadrilateral (seventy-eight by seventy-two meters) with round bastions at each corner, and at the center of the north and west walls. Defensive towers flanked narrow gates in the south and east walls.