A chapel in the Vatican, Rome, begun under Pope Sixtus IV in 1473 by Giovanni del Dolci, and decorated by (among others) Michelangelo. It houses the conclave that meets to select a new pope. Built to the proportions of Solomon's temple in the Old Testament (its height one-half and its width one-third of its length), it has frescoes on the walls (emphasizing the authority and legality of the papacy) by Botticelli, Ghirlandaio, and on the altar wall and ceiling by Michelangelo.