I certainly notice the vitality in Belfast, which wasn't there in the Seventies. There was a war going on then. Now there are cranes everywhere. There really is a sense of renewal and hope.
"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.