Newark is a city in Alameda County, California, in the East Bay region of the San Francisco Bay Area. It is unusual in being an enclave, entirely surrounded by the city of Fremont, and it forms the Tri-City Area together with Fremont and Union City. Newark was incorporated in September 1955, and its population is roughly 48,000. The city's development was shaped by its location and its self-reliant municipal style. Newark secured NewPark Mall as a super-regional shopping center at the intersection of Mowry Avenue and the Nimitz Freeway, giving the city a major retail and entertainment anchor, and it benefited from the completion of the Dumbarton Bridge and improvements to Interstate 880. The former Sun Microsystems campus near the bridge has since become the Pacific Research Center, reflecting the area's role in the Bay Area economy. Newark's western edge meets San Francisco Bay, where Cargill operates salt evaporation ponds, and the Don Edwards San Francisco Bay National Wildlife Refuge lies just to the south in Fremont, offering birdwatching, marshland trails, and open space along the Pacific Flyway. This bayfront setting gives the city an environmental dimension unusual for a built-out East Bay suburb. Public schools are provided by the Newark Unified School District, which serves the city, and nearby Ohlone College in Fremont offers higher education close to home. Transportation is a defining strength: the Dumbarton Bridge (State Route 84) crosses the bay toward the Peninsula, Interstate 880 runs along the city's eastern side, and BART stations in Fremont offer rail access to the wider region. The result is a compact, fully developed East Bay city with central location, shopping, and bayfront open space.