"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.
1 have always in my own thought summed up individual liberty, and business liberty, and every other kind of liberty, in the phrase that is common in the sporting world, "a free field and no favor."