The area around San Piero a Sieve holds several notable Medici-era sites within easy reach of the village. The Fortezza di San Martino, a sixteenth-century hilltop fortress built on the orders of Cosimo I, Grand Duke of Tuscany, has a well-preserved circuit of walls you can walk along for views across the Mugello valley. The Trebbio Castle, a few kilometres away, was commissioned by Cosimo de' Medici and reconstructed by the architect Michelozzo Michelozzi on the foundations of a feudal tower — guided visits run Tuesday through Friday (bookings: 055 845 8793). The Convento di Bosco ai Frati is a Franciscan monastery also rebuilt by Michelozzo for Cosimo, containing a small museum with a carved wooden crucifix attributed to Donatello; it is open daily (information: 055 848 111). The surrounding Apennine ridgelines offer good mountain walking trails for those who want to get out into the hills.