There has been a long debate about when the moais where built and why they were built. Moai’s are statues carved from volcanic stone from the Rano Raraku and are all monolithic, (carved in one piece). The largest moai erected is “Paro,” about 33 feet high and weighing about 83 tons. One unfinished sculpture has been found that would have been 69 feet tall and would have weighed about 270 tons. Less than one-fifth of the statues were moved to ceremonial sites and then erected. You will find that some of the moais had red stone cylinders (pukau) placed on their heads. These “topknots” were carved in a single quarry known as Puna Pau.
The quarries in Rano Raraku appear to have been abandoned abruptly, with many incomplete statues still in situ. However, the pattern of work is very complex and is still being studied. Practically all of the completed moai that were moved from Rano Raraku and erected upright on ceremonial platforms were subsequently toppled by native islanders in the period after construction ceased.
Although usually identified as “heads” only, the moai are actually heads and truncated torsos. In recent years, toppled moai have been found untouched and face-down. This led to the discovery that the famous deep eye sockets of the moai were designed to hold coral eyes. Replica eyes have been constructed and placed in some statues for photographs.
The statues were carved by the Polynesian colonizers of the island beginning by about A.D. 1000–1100. In addition to representing deceased ancestors, the moai, once they were erect on ceremonial sites, may also have been regarded as the embodiment of powerful living chiefs. They were also important lineage status symbols. By the mid-1800s, all the moai outside of Rano Raraku and many within the quarry itself had been knocked over. Today, about 50 moai have been re-erected on their ceremonial sites.