Philadelphia, Pennsylvania, the largest city in the state and one of the largest in the United States. It is the seat of Philadelphia County, with which it shares the same boundaries. Philadelphia is at the junction of the Schuylkill and Delaware rivers, about 50 miles (80 km) by water north of Delaware Bay, an arm of the Atlantic Ocean. Camden, New Jersey, is directly across the Delaware River, and New York City is about 90 miles (145 km) northeast.