Academy City (学園都市 Gakuen Toshi?), also known as Academy City of Science and Technology, is a landlocked sovereign city-state whose territory consists of a walled enclave within the Tokyo Metropolitan Employment Area. It is the primary setting of the Toaru Majutsu no Index series and its side stories. Academy City is composed of 23 districts, called School Districts which are simply numbered from one to twenty-three and each of these districts have a specific purpose.