For romance, Zattere Promenade delivers.
This broad, sun-trapping fondamenta runs the southern edge of Dorsoduro facing Giudecca island — a rare wide-open, breezy stroll in a cramped city, beloved for sunset, gelato from Nico, and watching big boats slide past. The catch: it's 'just a walk', so it's a free atmospheric add-on rather than a destination, and there's little to do but stroll and sit.