In the Rapa Nui language, the word “ahu” refers to the stone that acts as a support base for a moai. An average ahu measures around 1.20 metres tall. The ahu is considered a sacred ceremonial place whose job is to support the moai. The ahu are found along the coastlines of the island, with the main exception of Ahu Akivi. Clans typically had their own ahu, which is why it is common to find remains of villages nearby an ahu.

The largest ahu on Easter Island can be found at Ahu Tongariki, complete with 15 restored moai.