Castello offers enough to see and do as well that you could avoid the rest of Venice and not be bored (although that would feel a waste). Photographing in the Giardini della Biennale is a pleasure on its own as it is one of only a handful of parks in Venice and certainly the most beautiful. Wandering through the neighborhood further, you will find Saint Giovanni e Paolo hospital (awe-inspiring as it was built in an old church) and if you truly get lost you’ll be lucky enough to stumble upon Liberia Acqua Alta, literally overflowing with books.