Orvieto, Basilica Cathedral of S. Maria Assunta (or Duomo): the façade, whose building started at the end of the XIII century. The tricuspid design was by Lorenzo Maitani and executed by Maitani himself with the help of Pisa and Siena craftsmen (1320 -30). The execution was continued by Andrea Pisano (1347) and by Orcagna (1359) to whom we owe the rose window.