"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.
Everything in nature is formed upon the sphere, the cone and the cylinder. One must learn to paint these simple figures and then one can do all that he may wish.