 The first constitute a communication system between the main groups of constructions and access points to the site at prehispanic times.The second element, the roads, constitutes an interior road system, only that their functions could be diverse, as serving as a defense wall and limiting accesses to the site as well as internal communication.The Plaza de Armas is a huge rectangular, graded area bordered on the north and south ends by structures called wall-causeways which were used as roads.