Santa Ana is the county seat and second most populous city in Orange County, California and the 57th city in the United States. Now fully developed, Santa Ana has several distinct districts. The core of the city is the downtown area, which contains both retail and housing, as well as the Santa Ana Civic Center which is a dense campus of administrative buildings for both the city and the county of Orange. North of downtown is the "Midtown" district along Main St., home to entertainment destinations such as the Bowers Museum, MainPlace Mall, and the Discovery Science Center. The south end of the city is part of the South Coast Metro area, which is shared with the city of Costa Mesa. South Coast Plaza, a major shopping center, is the primary destination of this area, which also contains several high-rise office and apartment buildings.