They represent the greatest collection of antiques in the world. The museums are housed in the buildings erected by the various Popes from the 13 century. The palace's estimated 1,400 rooms, chapels, and galleries contain nearly 5 miles (8 km) of displays. In 1503 Julius II started to display a few classical work of art in the Belvedere Court; since then on, Popes continued and completed to gather and to select the greatest treasures of art. The collections are displayed in geographical and chronological order and cover ancient, modern and contemporary art works. For the interest and diversity of their treasures, the Vatican museums are a must for everyone visiting Rome.