Maps of most of the world have been deposited in the Library by the U.S. Defense Mapping Agency (recently reorganized into the National Imagery and Mapping Agency) and are kept in cases near the ramp on 3rd Level South. A collection of U.S. Geological Survey topographical maps is also stored nearby. The U.S. Government Publications Collection, located in the 3rd Level northwest, contains maps from the U.S. Central Intelligence Agency shelved under Pr Ex3.10/4:. Most general map needs can be met by using the atlases in the Reference Collection.