Baton Rouge is the capital and second-largest city of Louisiana. It is located in East Baton Rouge Parish and has an estimated population of 227,017. The metropolitan area, known as Greater Baton Rouge, has an estimated population of 774,327. The Baton Rouge-Pierre Part Combined Statistical Area, consisting of the Baton Rouge metropolitan area and Pierre Part micropolitan area, has a population of 797,208, making it the 64th-largest urban area in the United States. Baton Rouge 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 city’s residents from flooding 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. Baton Rouge is a major industrial and petrochemical center of the American South. The Port of Baton Rouge is the ninth largest in the United States in terms of tonnage shipped. The Baton Rouge region is called the "Capital Area."