Baton Rouge is the capital and second-largest city in Louisiana, United States. It is located in East Baton Rouge Parish, which has a population of 4,492,076 (as of the 2010 census). The city of Baton Rouge has an estimated population of 225,388 (2009 census estimate). The metropolitan area, known as Greater Baton Rouge, has an estimated population of 802,484 (2010). 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, 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.