San Sigismondo is a Renaissance church about 2.5 km east of Cremona's centre, built in the 15th century and decorated with an extraordinary cycle of Mannerist frescoes in the 16th century. The exterior is relatively plain and the setting — on a suburban road — gives no hint of what's inside. The interior is entirely frescoed from floor to ceiling, a dense and luxuriant programme that covers every surface in scenes from the life of the Virgin, the life of Christ, and allegorical compositions.
The quality is high — the Campi brothers and their workshop were among the leading fresco painters of northern Italy in the mid-16th century — and the church is remarkably uncrowded given the quality of the painting. It is one of those places that rewards sustained attention: the longer you look at the ceiling, the more you see. The church is about 30 minutes' walk from the Piazza del Comune; taxis are available or you can rent a bike from the centre.