Once part of the massive city walls, Torres de Quart was constructed between 1441 and 1460 on top of an earlier gate. At one point it housed a women's penitentiary, and later on it became a military prison. Be sure to look closely at the exterior and snap some shots of the large pock marks scarring the front of the towers. They were made when the gate was bombarded during the French siege of the city in the early 19th century. If you're lucky, you just may see some parrots that have taken residence there popping their heads out of the holes.