The 12th-century bronze St Rainerius Door (ca. 1180) by Bonanno Pisano originally provided access to the transept of the cathedral — the present door facing the Leaning Tower is a copy It mostly shows the life of Christ in 24 panels. Note the double scene on the square lower right: in addition to the Three Kings (Magie), the original sin of Adam and Eve are shown in the lower corner.
Cathedral Museum of Pisa (Museo dell’ Opera del Duomo)