Walnut Creek is a city in Contra Costa County, California, located east of the cities of Oakland and Berkeley in the East Bay region of the San Francisco Bay Area. Walnut Creek serves as a hub for the neighboring cities within central Contra Costa County, due in part to its location at the junction of the highways from Sacramento and San Jose (I-680) and San Francisco/Oakland (SR-24), as well as its accessibility by BART. The city’s total estimated population as of 2011 was 65,211.