The Treasure Cross of Saint John in Florence:
verso

The Cross of the Treasury of St. John: verso. The Cross made by Antonio del Pollaiolo on the back features the Annunciation within medallions, the Four Evangelists in the arms of the cross, and the Agnus Dei. Midway along the lower arm is a medallion with St. John the Baptist in the Desert. The statue of St. John the Baptist stands at the center of a small temple inspired by Brunelleschi and is surrounded by two angels. At the base of the cross is a relief of Calvary, surrounded by the walls of a miniature castle (an idealized symbol of Jerusalem) and populated by snakes and a skull.