Lovely place in the heart of the city, on a busy little walk through half way between Rialto Bridge and Piazza San Marco (NOT on the piazza, but 10min and 2 bridges walk away).
Beware! 67 steps in the heat is not for the feeble, but the airco is a godsend. Also beware the €40 surcharge if you arrive after 8pm plus the tourist tax €3pppd!