Chiesa di San Maurizio al Monastero Maggiore

San Maurizio is the Sistine Chapel of Milan — a 16th-century church whose interior is entirely covered in Renaissance frescoes by Bernardino Luini (Leonardo's most talented follower) and his school, creating a visual experience so overwhelming that the church has been called the most beautiful in Milan despite being virtually unknown to tourists. The exterior is plain grey stone that gives no hint of what's inside, which makes the moment of entering and seeing the frescoed walls for the first time genuinely startling.

The church is divided into two sections — the public nave and the nuns' choir, separated by a wall that originally allowed the cloistered Benedictine nuns to participate in services without being seen. Both sides are covered floor to ceiling in frescoes depicting biblical scenes, saints' lives, and decorative borders in vivid colour that has survived remarkably well. Luini's work combines Leonardo's sfumato softness with a Lombard clarity that gives his figures an accessibility that Leonardo's rarely achieve — the faces are tender, the landscapes are specific, and the colours are extraordinary.

The church sits on Corso Magenta, a few blocks from the Last Supper, and the combination of the two — Leonardo's masterpiece in one building, his follower's in another — provides a morning's worth of Renaissance painting that contextualises both artists. San Maurizio is free to enter, rarely crowded, and the absence of audioguides and gift shops means the experience is closer to discovering a hidden treasure than visiting an attraction. Come when the sun is hitting the south-facing windows for the best light on the frescoes.