Guided by his vision of a beautiful Madonna, 7th-century Saint Magno is said to have followed a small white cloud and built a church where it settled. Gracefully white, the marble building you see today dates from 1492, built by Mauro Codussi on an older foundation. Codussi's harmonious Renaissance design is best understood by visiting the interior; the Renaissance facade facing the canal was added later, in 1542, and the baroque facade facing the campo was added in 1604.
Of interest are three fine paintings: Our Lady of Mercy by Bartolomeo Vivarini, Santa Barbara by Palma il Vecchio, and Madonna with St. Domenic by Gianbattista Tiepolo. The surrounding square bustles with sidewalk cafés and a produce market on weekday mornings.