This shop, located between the Venetian and the Palazzo, is not your ordinary antiquarian bookstore.
The store is not huge, but their selection and collection is amazing. First-editions in pristine condition of Huckleberry Finn (green Webster binding) and Connecticut Yankee caught my eye. It's not just remarkable that they have the selection that they do... It's remarkable the condition that their books are in.
As mentioned in other reviews, this is basically a museum-grade artifact store. The storekeepers are not pretentious though. A sign politely invites guests: "Ask us to show you how to handle antique books." Very dignified, and a much better approach than the typical book-Nazi approach that you would typically find in a store with their inventory.
If your literature teacher in high school or college ever touched you, you owe it to him or her to stop in this store at least once if you are in the area.