A tiny boat-shaped island reached across the Ponte Fabricio (62 BC), Rome's oldest surviving bridge — and its appeal swings hard by season. Most of the year it's a quiet, slightly dead pause with a church, a hospital, and riverside steps, pleasant but thin. In summer it transforms: the 'Isola del Cinema' open-air film festival, bars, and food stalls fill the riverbanks and it becomes one of central Rome's best warm-night hangouts. Time your visit to that split.