This layer is a digital raster graphic (DRG) of a scanned nautical chart titled "Port of San Carlos." It was originally published by the U.S. National Geospatial-Intelligence Agency. (Chart number: 21122. 5th Ed., Jan-85; Scale:1:200000). Geographic areas covered by this map include the coast of Antarctica. This layer is part of a selection of digitally scanned and georeferenced maps from the Branner Library Map Collection at Stanford University.Historic paper maps can provide an excellent view of the changes that have occurred in the cultural and physical landscape. The wide range of information provided on these maps make them useful in the study of historic geography, and urban and rural land use change. As this map has been georeferenced, it can be used in a GIS as a source or background layer in conjunction with other GIS data.