"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.
Dune is the bestselling science fiction book of all time. It's something you really need to read in your lifetime. If you're going to read The Lord of the Rings, which everyone should, then you have to read Dune, too.
Life is not governed by will or intention. Life is a question of nerves, and fibers, and slowly built-up cells in which thought hides itself, and passion has its dreams.