Newark Liberty International Airport (IATA: EWR, ICAO: KEWR, FAA LID: EWR) is a major international airport in the U.S. state of New Jersey, serving the New York metropolitan area. The airport is located in both Newark and neighboring Elizabeth, straddling the boundary between Essex and Union counties Owned by the two cities, it is leased to its operator, the Port Authority of New York and New Jersey. Located approximately 4.5 miles (7.2 km) south of downtown Newark and 9 miles (14 km) west-southwest of Manhattan, it is a major gateway to destinations in Europe, South America, the Caribbean and Asia. It is the second-busiest airport in the New York airport system behind John F. Kennedy International Airport and ahead of LaGuardia Airport. The airport is near the Newark Airport Interchange, the junction between both Interstate 95 and Interstate 78 (both of which are components of the New Jersey Turnpike), and U.S. Routes 1 and 9, which has junctions with U.S. Route 22, Route 81, and Route 21. AirTrain Newark connects the terminals with the Newark Liberty International Airport Station, which is served by NJ Transit's Northeast Corridor Line and North Jersey Coast Line and Amtrak's Northeast Regional and Keystone Service. The City of Newark started building the airport in 1928 on 68 acres (28 ha) of marshland adjacent to Port Newark and U.S. Route 1.