The ramparts extend for almost 5km around the town, consisting of a double set of walls, inside of which an exquisite promenade has been laid out. Originally built in the 1C, and doubled in the 3C, these restored ramparts, which were further shored up in the 6C and 9C, are still in an extraordinary state of preservation. The first set of walls has 114 towers with a variety of shapes, and the second boasts 131. Of the four majestic and original gateways, three are still standing, including the Istanbul gate, a triumphal fortress-looking arch.