"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 truly believe that everything that we do and everyone that we meet is put in our path for a purpose. There are no accidents we're all teachers - if we're willing to pay attention to the lessons we learn, trust our positive instincts and not be afraid to take risks or wait for some miracle to come knocking at our door.