13th-century architecture and sumptuous marble envelop guests of this palazzo apartment in the shadow of the Scuola Grande di San Marco. From its entrance on a quiet square to its brick-walled private terrace, the villa offers a respite. But the domes of St. Mark’s Basilica and the arches of the Rialto Bridge are a 10-minute walk or less—and you can stop at famed pastry shop Rosa Salva on the way.