San Lorenzo is an early Renaissance-style church designed by Brunelleschi and constructed in Florence from 1421 to the 1460s, except for the facade, which was left uncompleted. Also by Brunelleschi is the Old Sacristy (finished in 1428).

The New Sacristy, more commonly called the Medici Chapel, is largely the work of Michelangelo, as are the celebrated Medici Tombs it houses. Michelangelo also designed the Laurentian Library, which is located off the cloister. The tombs of the grand dukes of Tuscany line the walls of the Baroque Chapel of the Princes, which was begun in 1604 according to plans of Ferdinand I de' Medici.

Attached to San Lorenzo is the Canons' Cloister and the Biblioteca Mediceo-Laurenziana. The cloister was added to San Lorenzo in the 15th century and designed by Filippo Brunelleschi. Works on the cloister began around 1420. The cloister has an open-air garden with lemon trees and other plants. On the walls, one finds plaques commemorating various events.

The importance of the Biblioteca Medicea Laurenziana, with its collection of nearly 11,000 manuscripts, is based mainly on two converging factors, both extraordinary: the specific nature of the Library's holdings and the character of its building, which was planned and partly realized by Michelangelo Buonarroti.

The story of this Library, from its core collection the Medici's private library to the various acquisitions which followed, has in fact been influenced by a constant aim, viz. the possession of books of a highly textual or esthetical quality.