We had a comfortable stay at Giacomo‘s bnb which overlooks a lively piazza in walking distance to the main attractions of the biennale. Giacomo welcomed us and was available throughout our stay. The only drawback was that the diners of the adjacent restaurant are seated outside below the bedroom and the piazza attracted all kinds of rowdy groups throughout Friday night(better on Saturday/Sunday). Ear plugs might be a good idea if you plan to sleep before midnight.