Is the place where the great buns that covered the moai were extracted and prepared (most of them did not carry them). The ancient islanders opened this quarry belatedly in one of the many adventitious cones of the island. The red rock used to make the pukao is very soft, since it is formed by volcanic slag. The real difficulty the sculptors faced was extracting these hats from the craters, and particularly, rolling them over carefully in order to transport them without damaging them. Many believe that due to the lack of instruments like cranes, whoever lifted the moai first placed the pukao on their heads, and then lifted the whole set with a system which consisted of piling up stones and using levers. Heyerdahl carried out the experiment in Anakena in 1956. The weight of the pukao ranged from 9 to 12 tons.