California is the most populous state in the United States and the third most extensive by area. Located on the western (Pacific Ocean) coast of the U.S., California is bordered by Oregon to the north, Nevada, to the east and northeast, Arizona to the southeast and it shares an international border with the Mexican state of Baja California to the south. The state capital is Sacramento. Los Angeles is California's most populous city, and the country's second largest after New York City. The Greater Los Angeles Area and the San Francisco Bay Area are the nation's second- and fifth-most populous urban regions, respectively. California also has the nation's most populous county, Los Angeles County, and its largest county by area, San Bernardino County.
California's diverse geography ranges from the Pacific Coast in the west to the Sierra Nevada mountain range in the east; and from the redwood–Douglas fir forests in the northwest to the Mojave Desert in the southeast. The Central Valley, a major agricultural area, dominates the state's center. Though California is well-known for its warm Mediterranean climate, the large size of the state means it can vary from moist temperate rainforest in the north, to arid desert in the interior, as well as snowy alpine in the mountains.