"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.
The result is - document destruction - we're really not going to be able to prove beyond a truth the negatives and some of the positive conclusions that we're going to come to. There will be always unresolved ambiguity here.