Lido di Venezia is a real time commitment — fit it in only if it's a priority.
Allow Half day.
A 15-minute vaporetto delivers you to actual sand, the open Adriatic, bikeable streets, cars(!), and faded Liberty-style grand hotels — a genuine palate-cleanser when the stone city overwhelms, and the only place to swim. The catch: the free public beach stretches are modest and the nicest sand is private/paid via the hotels, the architecture is more shabby than glamorous outside festival season, and it feels a world away from canal Venice.