"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 think its so cool that you can pick up the guitar and create something that didn't exist 5 minutes ago. You can write something that no ones ever heard before. You have music at your fingertips.