The Ponte Santa Trìnita is a Renaissance bridge constructed by the Florentine architect Bartolomeo Ammannati when the original bridge - built first in wood then in stonewas destroyed in the previous centuries by the Arno floods. The Ammannati bridge was commissioned by Cosimo I de’ Medici and was realized according to the project of Michelangelo from 1567 to 1571. In the central arch, on both sides of the bridge, two heads of raw stand out as symbol of strength and fighting spirit. The head facing the Ponte Vecchio guards the city from the floods coming from the Casentino countryside, the head facing Ponte alla Carraia defends Florence from the attack of foreign armies or - according to another tradition - from the eternal enemies Pisa’s citizens. Destroyed by retreating German troops in 1944 the bridge was reconstructed in 1958 with original stones raised from the Arno river.