Concierge.com's insider take:

The Medicis' parish church stands on the site of one of the city's oldest places of worship. The present building was designed by Brunelleschi; work on it began in 1421 and continued well into the 1460s. The unfinished rough brick facade contrasts with the cool, calm interior in gray pietra serena. Two fabulous bronze pulpits near the front are by Donatello; decorated with panels depicting scenes from Christ's Passion, they were his last works and had to be finished by his pupils. The second chapel on the right houses The Marriage of the Virgin by the Mannerist painter Rosso Fiorentino. Don't miss the Old Sacristy off the left transept, a decorative tour de force by Brunelleschi and Donatello. A gateway on the left of the facade leads to Michelangelo's Biblioteca Mediceo-Laurenziana (Mon–Sat 8:30 a.m.–1:30 p.m.), commissioned by Medici Pope Clement VII to house the family's priceless collection of manuscripts. The reading room is off-limits to tourists, but the vestibule with its extraordinary Mannerist staircase can be admired by all.

Open Monday through Saturday 10 a.m. to 5 p.m., also Sunday 1:30 p.m. to 5:30 p.m. in summer.