Considered one of Florence's most harmonious examples of Renaissance architecture, this unfinished basilica was the Medici parish church and mausoleum. It was designed by Brunelleschi in 1425 for Cosimo the Elder and built over a 4th-century church. In the solemn interior, look for Brunelleschi's austerely beautiful Sagrestia Vecchia (Old Sacristy) with its sculptural decoration by Donatello. Michelangelo was commissioned to design the facade in 1518, but his design in white Carrara marble was never executed, hence the building's rough, unfinished appearance.
Inside, columns of pietra serena (soft grey stone) crowned with Corinthian capitals separate the nave from the two aisles. The gilded funerary monument of Donatello – who was still sculpting the two bronze pulpits (1460–67) adorned with panels of the Crucifixion when he died – lies in the Cappella Martelli (Martelli Chapel) featuring Fra' Filippo Lippi's exquisitely restored Annunciation (c 1440).
Donatello's actual grave lies in the basilica crypt, today part of the Museo del Tesoro di San Lorenzo (San Lorenzo Treasury Museum); the crypt entrance is in the courtyard beyond the ticket office. The museum displays chalices, altarpieces, dazzling altar cloths, processional crucifixes, episcopal brooches and other precious sacred treasures once displayed in the church. Across from the plain marble tombstone of Donatello is the tomb of Cosimo the Elder, buried inside the quadrangular pilaster in the crypt supporting the basilica presbytery – his funerary monument sits directly above, in front of the high altar in the basilica.