"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.
I've worked for 55 years. I'm going to take a little time off, to tell you the truth. It's just that now in the last couple of weeks, Gelman is pouring it on. 'Farewell to Regis!' It's getting embarrassing.