In true education, anything that comes to our hand is as good as a book: the prank of a page- boy, the blunder of a servant, a bit of table talk - they are all part of the curriculum.
"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.