Jacksonville is the largest city in the U.S. state of Florida and is the county seat of Duval County, with which it is consolidated. Located in Northeast Florida, and at the mouth of the St. Johns River, it is a major seaport city and the center of the Jacksonville metropolitan area. With an estimated 913,010 residents as of 2017, Jacksonville is the most populous city in both the state of Florida and the southeastern United States. It is estimated to be the 12th most populous city in the United States and is the largest city by area in the contiguous United States. The Jacksonville metropolitan area has a population of 1,626,611. It is the 34th largest MSA in the United States and fourth largest in the state of Florida. The city is situated on the banks of the St. Johns River, in the First Coast region of North Florida, about 25mi south of the Georgia state line and 340mi north of Miami.