Florence Baptistery
Among the most famous works of art employing the barbed quatrefoil are the bronze panels on the south doors of the Florence Baptistery (1330–36) by Andrea Pisano, the bronze panels of the north doors of the Florence Baptistery by Lorenzo Ghiberti, Filippo Brunelleschi's competition entry for the same doors ("The Sacrifice of Isaac"), as well as "Head of an Angel" by Piero della Francesca.