Built around 1200 on the order of King Philippe Auguste, this gate bears witness to the fortifications of that time, with its north facade, very little altered: it still presents its defensive system characterized by its side towers in spur and a set of lines of biases that ensured maximum protection and effectiveness to its defenders.
Under the vault one can clearly distinguish the grooves where the two portcullis slid which ensured the closure of the door and constituted a real airlock, reinforced laterally by four loopholes which allowed the defenders to attack in crossfire an enemy who had crossed the first portcullis. Stunners, placed in front of the first portcullis and after the second completed this device. Do not imagine a drawbridge, a device still unknown at the time of its construction.
Within the walls, there are still the stairs which gave access to the floor of the door and to the curtain walls which surrounded the city over a circumference of nearly 2 km.