The present Church of San Pietro in Montorio de Roma was founded in 1480, thanks to the sponsorship of the Catholic Monarchs, becoming a Franciscan convent. During the 530 years of its existence, it has undergone some major transformations which turned it into one of the temples of greatest relevance in Rome. Important Renaissance and Baroque artists such as Peruzzi, Rafael, Sebastiano del Piombo, Vasari, Volterra, Maderno and Bernini worked on it. Its building on Janiculum Hill on the Monte Aureo, with its golden sand, has meant impprtand damage to it over its existence, now seen in serious intensity. The article displays the results of our research, going more deeply into the damage, the causes and the solutions proposed for its conservation.