Greater Los Angeles is the most populous metropolitan area in the U.S. state of California, encompassing five counties in Southern California extending from Ventura County in the west to San Bernardino County and Riverside County in the east, with the city of Los Angeles and Los Angeles County at its center, and Orange County to the southeast. The Los Angeles–Long Beach combined statistical area (CSA) covers 33,954 square miles (87,940 km²), making it the largest metropolitan region in the United States by land area. The contiguous urban area is 2,281 square miles (5,910 km²), whereas the remainder mostly consists of mountain and desert areas. With an estimated population of almost 18.6 million, it is the second-largest metropolitan area in the country, behind New York, as well as one of the largest megacities in the world.