"Ahu" are stone platforms on which many moai sit. There are 313 known ahu and 125 of these carry moai. The biggest, Ahu Tongariki is 220 m (720 ft), and had the most (15) and tallest moai.
A man has no religion who has not slowly and painfully gathered one together, adding to it, shaping it and one's religion is never complete and final, it seems, but must always be undergoing modification.