The moais of Easter Island are large statues built to honor ancestors, crafted from basalt and tuff over nearly 1,000 years, with sizes up to 21.6 meters. The moais, primarily located at Rano Raraku quarry, were transported to coastal platforms called ahus, facing the island, except for Ahu Akivi which faces the ocean. The decline of the civilization is attributed to resource over-exploitation and tribal conflicts, leading to the emergence of a new culture known as the Tangata Manu between 1680-1850.