The most important monument founded by Branda is the Collegiate church, built on the top of the upper hill of the village, on the site of the ancient castle, which remains of the entrance portal are still visible. The church and the Baptistery are part of the Collegiate Museum. Both have been decorated by Masolino da Panicale, one of the most important painters in Florence at the time of the transition from International Gothic to Renaissance. Lorenzo di Pietro called "il Vecchietta" and Paolo Schiavo worked with him in the Collegiate apse. But Masolino left in Castiglione his masterpiece: the frescoes of the Baptistery, with their fascinating fusion of landscapes and architectures, religious history and Renaissance setting, make the chapel, painted in every centimetre, one of the best achievements of the early Italian Renaissance.