Central Luzon, designated as Region III, is an administrative region in the Philippines. The region comprises seven provinces: Aurora, Bataan, Bulacan, Nueva Ecija, Pampanga, Tarlac, and Zambales; and two highly urbanized cities, Angeles and Olongapo. San Jose del Monte is the most populous city in the region. The region contains the largest plain in the country and produces most of the country's rice supply, earning itself the nickname "Rice Granary of the Philippines". It is also the region to have the most number of provinces.