During excavation work in the Ceremonial Center of the Paracas-Nasca Culture at Cahuachi, Peru, it was observed that the objects uncovered from sand showed extreme deterioration. In 1987 the building technique and the destructive climatic agents were studied. Laboratory investigations were aimed at the determination of phase composition and structure of materials found in the Ceremonial Center. Besides harmful climatic conditions, the process of destruction is also due to water-soluble salts, ion-exchange processes in montmorillonite (which is the main component of adobe, mortars, and tile floors), as well as the action of acidic atmospheric pollution. The results of these studies contributed to a conservation program for rescuing the Ceremonial Center.