We took the Vaporetto (15 min) from San Marco to Lido, then we rented bikes from a place very close to the Vaporetto stop. They give you a map of where you can ride and a few points of interest on the way. It was one of the nicest diversions while in Venice if you have a half a day to devote to it. There are cars on Lido, so be careful. There are a lot of bikers on the island though, so we never felt in danger.
Many buildings on Lido are shuttered or vacant. It is apparent that hard times have hit the island from a tourist standpoint. Hopefully things perk up during beach season. The Grand Hotel des Bains is downright depressing to see boarded up. Even the buildings where the Venice Film Festival is held are looking shabby.
All in all, we would do it again.
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