South Orange County is more residential, wealthier, more Republican, less racially diverse and more recently developed. Irvine, the largest city in the region, is an exception to some of these trends, being a major employment center and having an Asian plurality (although Irvine's Asian population tends to be East Asian rather than Southeast Asian). South Orange County almost always includes Irvine, Newport Beach, and the cities to their southeast, including Laguna Beach, Mission Viejo, and San Clemente. Costa Mesa is sometimes included in South County, although it is located predominantly to the west of the Costa Mesa Freeway. Irvine is located in a valley defined by the Santa Ana Mountains and the San Joaquin Hills, while much of South Orange County is very hilly.