The nondescript modern town of Castiglione Olona, 8km south of Varese off the SP42 road, contains a quite extraordinary gem. The old centre was largely rebuilt under the auspices of its most favoured son, Cardinal Branda Castiglioni (1350–1443), in Florentine Renaissance style. Via Branda leads from the central square up to the Museo della Collegiata, a church that contains the town’s masterpiece.
Inside its baptistery, Florentine master Masolino da Panicale carried out a series of frescoes on the life of St John the Baptist in 1435. Also in the complex is a church with exquisite 15th-century frescoes by three Tuscan painters, and a small museum with ecclesiastical treasures, including 15th-century tomes with illuminated lettering.