The grandiose domus de janas of Sant'Andrea Priu are among the most important in Sardinia. Twenty impressive sepulchres were dug between the fourth and third millenium BC in a 10m-high trachyte wall facing south; some of them, including the Tomba del Capo (250m2 and 18 rooms), were refashioned as Christian places of worship in the Middle Ages, as shown by the handsome series of frescoes, which have been recently restored.