The museum is composed of the New Sacristy (Sagrestia Nuova) by Michelangelo, the Chapel of the Princes (Cappella dei Principi), the Crypt that houses the tombs of the Medici Grand Dukes and their family members, and the Lorenese Crypt, which includes the remains of the Lorena family, as well as the funerary monument to Cosimo the Elder, "Pater Patriae.”

The museum also holds a portion of the precious Treasury of the Basilica of San Lorenzo.  

For more detailed informations, see website