Several organizations make Environmental Systems Research Institute (ESRI) shape files freely available and you can adapt them for your purposes. Using RgoogleMaps is easy, and we have seen that it offers very little control over map elements and plotting. Importing shape files, on the other hand, gives us total control. We should prefer this approach when we need fine control over the rendering of individual elements rather than just plotting a map image as a whole. The rgdal package offers the functionality to download shape files into R in a format that the sp package can handle.