Southern Illinois (also known as "Little Egypt" or "Egypt") is the southern third of the state of Illinois. With the area code 618, the southern part of Illinois is geographically, culturally, and economically distinct from the rest of the state. It is considered a part of downstate Illinois. The region is bordered on three of four sides by the most voluminous rivers in the United States: the Wabash and Ohio rivers to the east and south, and the Mississippi River and its connecting Missouri River to the west.