"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 thing is, I don't believe in most of what's done. The amount of financial and imaginative energy that's put into mediocrity is just amazing which I find to be fundamentally offensive as a human being.