"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.
Someone who has set out in the vehicle of a bodhisattva should decide that `i must lead all the beings to nirvana, into that realm of nirvana which leaves nothing behind'. What is this realm of nirvana which leaves nothing behind?