Introduction to the Map Gallery: The Map Gallery is located on the west side of the Belvedere Courtyard and is 120 meters long. It collects all maps of Italy, Pope Gregory XIII (January 7, 1502 - April 10, 1585) Ignazio Danti of Perugia was commissioned to paint the walls, and it took Ignazio Danti three years (1580–1583) to complete 40 paintings; the decoration of the gallery ceiling is the work of a group of Mannerist painters such as Cesare Nebbia and Girolamo Muziano.