To the south, the church is sided by a brick bell-tower with a stone base characterized by a strong inclination. Numerous elements of this church remind of the Romanesque-Pisan architecture of the Dome, such as the use of marble and the façade division in five arcades that rest on semicolons. The church and the monastery of San Michele degli Scalzi were built upon a pre-existing oratory around the first half of the XII century, when the Republic of Pisa was at its apex. Between 1152 and 1171, the structures were finished and this complex was given to the Benedictine monks, called "scalzi", who worked to embellish the building beyond practising their religious activity. In 1168, they finished a cycle of frescoes on the life of Isaac. At the beginning of the XVII century, the church was modified. Some vaults were added to the to the nave and isles and windows were created instead of the embrasures. In 1627, the cloister was completed. Also during the XX century numerous works were made, but during the Second World War the church underwent new damages and the bell-tower was the only structure saved. Unfortunately, its unlucky destiny did not stop with the end of the conflict. The flood of the river Arno in 1949 restarted its process of decay., but now the monastery has been completely restored. Inside the church, it is possible to admire a XIII-century cross coming from the church of San Giovanni Decollato with a style that is typical of Pisa and Lucca and of which Berlinghiero was the main supporter. Yet, this work was attributed to the juvenile production of Giunta Pisano because of a certain Byzantine influence.