You may feel as if you're walking through a Hollywood set -- but this is the real thing. The harbor fort, built on the site of a series of earlier forts, went up between 1523 and 1540, and although greatly restored, it is essentially the Venetian original. Both its exterior and interior are impressive in their dimensions, workmanship, and details: thick walls, spacious chambers, great ramparts, cannonballs, and Lion of St. Mark plaques. It's well worth an hour's visit.