Getting the data
Lex will make use of two map layers: a basemap layer that displays a shaded-relief raster image, and a landmark layer that shows the individual landmarks based on a set of place names. Both of these datasets can be downloaded from the Natural Earth Data website. Visit http://www.naturalearthdata.com and click on the Get the Data link to jump to the Downloads page.
The basemap data can be found by clicking on the Raster link. We'll want the highest-resolution data available, so use the link in the Large scale data, 1:10m section.
While you could use any of these datasets as a basemap, we will download the Natural Earth I with Shaded Relief, Water, and Drainages dataset. Make sure you download the high-resolution version of this dataset so that the raster image will still look good when the user has zoomed in.
For the landmarks, we'll be using the "populated places" dataset. Go back to the main downloads page and click on the Cultural link in the Large scale...