Jersey City is the seat of Hudson County, New Jersey, United States. As of the 2010 United States Census, the population of Jersey City was 247,597, making it New Jersey's second-largest city after Newark. and the 78th most populous city in the U.S.Part of the New York metropolitan area, Jersey City lies between the Hudson River and Upper New York Bay across from Lower Manhattan and the Hackensack River and Newark Bay. A port of entry, with 11 miles (17.7 km) of waterfront and significant rail connections, Jersey City is an important transportation terminus and distribution and manufacturing center. Service industries have played a prominent role in the redevelopment of its waterfront and the creation of one of the nation's largest commercial real estate markets.