"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'm physically completely mal-coordinated. My best friend used to make me run for the bus just to give herself a quick, cheap laugh because I definitely don't have that sophisticated cool thing down.