"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.
This is at the heart of all good education, where the teacher asks students to think and engages them in encouraging dialogues, constantly checking for understanding and growth.
I envy the sensibility in Europe, appreciating beauty in women as they age. I'm going to go that way. I might dye my gray hair for a bit, but beyond that the buck stops. I'm not having any work done.