Multiple maps are generally used when displaying the same data over separate time periods (in such cases, a common scale and legend are important) or when displaying differing geographic extents that all have related data. Additionally, multiple maps may be required when ancillary data that contribute to the overall map purpose need to be displayed but are not central to the main purpose. Multiple maps on one layout can be highly informative as they offer on-the-fly analysis by the viewer of the map, thus making the map interactive and more likely to endure in the viewer’s memory. Whether your layout will contain one map or many, the map element(s) will be your primary means of conveying information to the viewer, and therefore will likely be the layout element that takes, by far, most of your time to create and polish. Indeed, Chapter 6 of this book is devoted solely to the techniques used in developing and refining the map element. It can be designed in conjunction with the rest of the layout or it can be designed prior to the layout design process.