Kero (Waisted Cup), 400-1000. The kero is a distinctive Tiwanaku vessel form, imitated by the later Inka, who used the cups in political and religious ceremonies. It is assumed that the same was true at Tiwanaku, where impressive stone figures, perhaps rulers, hold keros as though they are emblems of authority. Perhaps, like the Inka, the Tiwanaku used keros to drink chicha, a corn beer shared to cement bonds of mutual obligation among allies.