"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.
The relationship between the public and the artist is complex and difficult to explain. There is a fine line between using this critical energy creatively and pandering to it.