The Basilica of San Lorenzo is one of the main Catholic places of worship in Florence , located in the square of the same name in the historic center of the city. It is one of the churches that contend for the title of the oldest in the city and has the dignity of a minor basilica [1] . Near the church there is the tourist market of San Lorenzo .

External architecture
The façade of San Lorenzo is a sloping hut, with exposed stone on which three curved portals open. The right side is in smooth stone, decorated with an order of blind arches and pilasters. On this side we can also see the outside of the New Michelangelo's sacristy , with a small dome covered with scales, completed by a lantern with marble columns.

Above, above the tiburio , is the large dome of the Princes' chapel , covered by roof tiles.

On the back of the church (with access from the back on Piazza Madonna degli Aldobrandini) opens the grandiose Chapel of the Princes , with its large dome that in Florence is the second largest after that of the cathedral .

Internal architecture
The church has a Latin cross with three naves , with chapels along the piedicroce and the sides of the transept. At the intersection of the arms there is a dome . The plant, as in other works by Brunelleschi, is inspired by other works of the Florentine medieval tradition, such as Santa Croce , Santa Maria Novella or Santa Trinita , but starting from these models Brunelleschi was inspired by something more rigorous, with revolutionary results. . The fundamental innovation lies in the organization of the spaces along the median axis by applying a module (both in plan and in elevation ), corresponding to the size of a square span , with the base of 11 Florentine arms , about the same of the Spedale degli Innocenti (10 Florentine arms), built since 1419 . The use of the regular form, with the consequent rhythmic repetition of the architectural members, defines a perspective scan of great clarity and suggestion. The two side aisles have been defined as the symmetrical development of the loggia of the hospital, applied for the first time inside a church: here too the use of the square span and the vaulted ceiling generates the sensation of a space marked as a regular series of imaginary cubes surmounted by hemispheres.
The side walls are decorated with pilasters that frame the round arches of the chapels. The latter, however, are not proportionate to the form and are thought to be a tampering with the original project of Brunelleschi, implemented at least after his death ( 1446 ). Moreover, the rationality of the plant in the piedicroce does not find a comparison of similar lucidity in the transept, since it is here that Brunelleschi probably had to adapt to the foundations already started by Dolfini. On the basis of surveys, foundations studies, archive surveys and a drawing by Giuliano da Sangallo of the early fifteenth century [5] it was rebuilt that the original design should include a round of square-shaped chapels (instead of rectangular as are now), with vaulted ceiling and apse on the back wall, which also continued in counter-façade and the heads of the transept and the presbytery, where pairs of symmetrical chapels were provided on each end: a revolutionary model, which the architect tried to apply years later, with more consistent results, in the Basilica of Santo Spirito .
The interior is extremely bright, thanks to the series of arched windows that runs along the clarinet . The columns rest on short plinths , have smooth stems and end in the innovative "Brunelleschi's nut", composed of the Corinthian capital and a cubic pulvinus , composed of a frieze with reliefs of angelic protome and grids of St. Lawrence. The arches of the nave are round, dominated by a protruding cornice.