Taiwan, officially the Republic of China, is a state in East Asia. Originally based in mainland China, the Republic of China now governs the island of Taiwan, which makes up over 99% of its territory, as well as Penghu, Kinmen, Matsu, and other minor islands. Neighboring states include the People's Republic of China to the west, Japan to the east and northeast, and the Philippines to the south. Taipei is the seat of the central government. New Taipei, encompassing the metropolitan area surrounding Taipei proper, is the most populous city.