Dominating the town, this 13 C castle is now the town hall and has preserved its inner castle, keep and merlons. In the courtyard decorated with shields, the stone table marks the site where justice prevailed. There are two storeys of wooden balconies and an external staircase. The library, the Great hall with its ceiling with paintings and the chapel frescoed by Taddeo Gaddi are open to the public. There is an attractive view over the mountains, towards Camaldoli and La Verna.