"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.
Four men are missing R., Sorel and two emigrants. They set out this morning after buffalo, and have not yet made their appearance whether killed or lost, we cannot tell.