Baton Rouge is a major industrial, petrochemical, medical, and research center of the American South. The Port of Baton Rouge is the ninth largest in the United States in terms of tonnage shipped, and is the farthest upstream Mississippi River port capable of handling Panamax ships. The Baton Rouge area, also known as the "Capital Area", is located in the southeast portion of the state along the Mississippi River. It owes its historical importance to its site upon Istrouma Bluff, the first bluff upriver from the Mississippi River Delta, which protects the citys residents from flooding, hurricanes, and other natural disasters. In addition to this natural barrier, the city has built a levee system stretching from the bluff southward to protect the riverfront and low-lying agricultural areas.