Easter Island, discovered in 1772, is famous for its 600 massive stone statues, the <i>moai</i>. A Unesco mission carried out in 1982 had as object the study of the state of conservation of the matter, which is volcanic rock. Various tests have determined its properties and the causes of its deterioration-rain, temperature changes, micro-organisms and salts. The experts have recommended that the restoration work be accelerated and carried out under the auspices of Unesco.