Since 1943 what used to be called the City of Tokyo is technically "Tokyo-to" (Tokyo Metropolis), but what area that designates depends on the context. The smallest area--what is most commonly thought of as the city of "Tokyo" comprises the central 23 wards (ku) of 598 square kilometers of densely built-up area around the Imperial Palace and downtown. It has about 8.5 million people. As an administrative unit, however, Tokyo-to is a wider area under the Tokyo government. It includes 26 cities of The Tama District to the southwest and two groups of small islands to the far south. It extends Tokyo-to's area to 2,162 square kilometers and pushes the population to nearly 12 million. Finally, The [Greater] Tokyo Metropolitan Area further includes neighboring Saitama, Chiba, and Kangawa Prefectures, which greatly expands the area to 13,508 square kilometers and the population to nearly 29 million. For our purposes, "Tokyo" will primarily mean the central ward area.