The Church of Santa Maria delle Carceri is located in the square bearing the same name, flanked by the imposing Emperor's Castle. It was built on the ruins of an ancient prison by Giuliano da Sangallo (1485-92) as commissioned by Lorenzo the Magnificent. With harmonious proportions, the church has a Greek cross floor-plan, typical of the Renaissance period. The upper part ends the structure with a small dome with Brunelleschi style shapes and a lantern window. The external covering (unfinished) in white alberese and green serpentine, gives a sense of lightness to the structure. The classical style interior is brightened by a majolica frieze that runs at the top along the perimeter of the church attributed to Andrea della Robbia. The high altar designed by Sangallo, holds the miraculous fresco of the Madonna delle Carceri between the Saints Leonardo and Stefano (fourteenth century). There are valuable stained-glass windows made in 1491 according to the design of Domenico Ghirlandaio.