Human remains dating back to AD 600 continue to be uncovered at an archaeological dig in the Tonala community of Plan de Guaje. So far, the excavation has revealed a circular altar about six meters in diameter, which archaeologists say probably was used for ceremonial purposes. The National Anthropology Institute (INAH) is supervising the dig, which has been going on for nine months and may continue for several more. Apart from the human remains and the stone circle, few objects have been recovered, so archaeologists are reluctant to speculate on exactly what went on at the site.