Surprisingly overlooked by the crowds, this museum on the northern (street) side of the cathedral safeguards treasures that once adorned the duomo, Baptistry and campanile. It is one of the city's most impressive museums.

Make a beeline for the glass-topped courtyard with its awe-inspiring display of seven of the original 10 panels from Ghiberti's glorious masterpiece the Porta del Paradiso (Door of Paradise), designed for the Baptistry.

The nearby large room is devoted to statuary from Arnolfo di Cambio's original never-to-be-completed Gothic facade. Pieces include several by Arnolfo - Pope Boniface VIII, The Virgin and Child (with its somewhat strange glass eyes) and Santa Reparata - as well as Donatello's 1408 statue of St John, which was the sculptor's first large-scale work. Next door, the smaller space is home to exquisite marble panels from the duomo's coro (choir), carved by Baccio Bandinelli and Giovanni Bandini in 1547.

On the stair landing is the museum's best-known piece, Michelangelo's Pietà, a work he intended for his own tomb. Vasari recorded in his Lives of the Artists that, dissatisfied with both the quality of the marble and of his own work, Michelangelo broke up the unfinished sculpture, destroying the arm and left leg of the figure of Christ. A student of Michelangelo's later restored the arm and completed the figure.

Continue upstairs, where a pair of exquisitely carved cantorie (singing galleries) or organ lofts - one by Donatello, the other by Luca della Robbia - face each other. Originally in the cathedral's sacristy, their scenes of musicians and children at play add a refreshingly frivolous touch amid so much sombre piety. There are also several carvings by Donatello here, including his Prophet Habakkuk, originally in the campanile, which has always been known as ' lo zuccone' (big head). Vasari wrote that he visited Donatello in his studio one day to find him looking intensely at this extremely life-like statue and commanding it to talk (he'd obviously been working far too hard!). Don't miss the same sculptor's wooden representation of a gaunt, desperately desolate Mary Magdalene in the same room, a work completed late in his career.