Online bookstores have highly thrived and changed consumer behaviors in these years. However, most customers go to online bookstores only when they have specific targets. One reason is that the current web interfaces are usually too complex and cluttered for users to browse. In addition, current visualization interfaces only display the results associated with a single attribute, thus requiring users to interact intensively to find their targets. Inspired by the user experiences (UX) in physical bookstores, we present Bookwall, an online bookstore interface which comprises two components: Category Map and Wall View, enabling users to find their targets more efficiently and releasing users from the burden of complicated operations. Specifically, the category map produces a map with a "natural" map-like look, providing an overview of the clusters and neighborhood of book categories. The wall view enables displaying query results satisfying dual query attributes simultaneously. The results show that Bookwall can provide the users a favourable alternative visualization.