The Basilica of Santa Maria degli Angeli is the seventh largest church in the world. It was begun in 1569 by Pope Pius IV, and built to the designs of Galeazzo Alessi. Work continued until 1667, when the dome was added and later, in 1684, the bell tower was erected. The façade, once a neo-classical style, was altered to neo-baroque in 1928. Inside are 3 naves with a series of side chapels. The exterior is decorated with frescoes of the 14th and 15th Century by Andrea d‘Assisi.