Walls surrounding all or part of a site center have long been recognized as important archaeological features, but often little consideration is given to their function beyond their apparent defensive use. Recent investigations of the site wall at Chichen Itza in the northern lowlands highlight the need for a strong framework within which to interpret wall features, as well as the importance of viewing wall structures as dynamic systems that may have served multiple functions simultaneously or over time. Such a framework will allow researchers to understand site walls as part of larger systems of social control in addition to providing insight into the practice of warfare among the ancient Maya. In the case of Chichen Itza, the wall that surrounds a large part of the ceremonial center appears to have been built originally as a symbolic structure, part of an elite program of separating the ceremonial precinct from its mundane surroundings. In contrast, late additions to the wall indicate the possibility of an increased need for defense in the site center.