Tula the famed city of Tolan (they think). When Teotihuacan was in decline about the time that the Roman Empire was also falling apart people left Teotihuacan and Tolan was born. It because the beacon of civilization in the central valley until it too declined several hundred years later. The Aztecs passed through here and sacked it only to later claim they were decendents of the mighty Toltecs. 

I've wanted to come here for quite a while but it's a bit of a trek out to Tula by bus. I'm glad we went though.