VENICE — A private island in the northern Venice Lagoon with a Napoleonic fort converted into a residence has been listed for sale by Lionard Luxury Real Estate, the Florence based agency specialising in prestige Italian properties. The Isola di Crevan (Island of Crevan) sits seven kilometres from Venice with direct views of Burano and Torcello, offering 5,700 square metres of gardens, orchards, and waterfront silence reachable only by boat or helicopter.