"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.
I really wish we could stay longer in the countries we visit, but I've been lucky to have visited most of them before, because I've done a tremendous amount of travel.
John Wesley Powell led the first expedition down the Grand Canyon in 1869. He was the first to use the name "Grand Canyon" after it had previous been known as the "Big Canyon" or "Great Canyon".