Liberia Aqua Alta is a bookstore on the canal that was a sight to see. It's the most interesting, disorganized, water flooded bookstore with books in baths, boats, and a even a gondola. It also has a nook with a view, and a staircase of moldy books to another view of the canal. If you're into odd sights, check this one out. 

Location: Calle Longa S. Maria Formosa, 5176/b, 30122 Castello, Venezia VE, Italy