"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.
Even now, when I try and think of band names just randomly, I'm so thankful that 'fun.' is the name of the band. I never really think twice about it. It is so simple and so easy.