"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.
There is both a skill factor and an effort factor in dream recall. People can develop dream recall skills, such as lying still in the morning and writing down whatever comes to mind.
I care not what black spiritual crisis we may come through or what delightful spiritual canaan we may enter, no blessing of the christian life becomes continually possessed unless we are men and women of regular, daily, unhurried, secret lingerings in prayer.