[History]
Academy City (学園都市 GakuenToshi) is the primary setting of the Toaru Majutsu no Index series and its side stories.
As the city's name suggests, it is a city of several schools and institutions of higher learning from kindergarten to university level that learn side-by-side along with the scientists who research on psychic powers and higher technology, the latter being one of the primary reasons for its establishment. It is the most advanced city in the human world and its technology is said to be 30 years ahead of what's 'outside' of Academy City.
Academy City's total population is about 2.3 million with 80% of them being students and 1/8 of those students living in the city dorms. Of the entire student population, about 60% of them have the ability to demonstrate even a slight amount of psychic ability (these are Power Users of Levels 0-5). The remaining 20% of the students in Academy City pursue other subjects instead of going under the Power Curriculum Program
Academy City's technology is thirty years ahead of its time and thus, has accessibility to a more sophisticated array of measures to ensure security across the city.
The city limits leading outside are lined with walls, accessible only through entry points which require persons to have permission to enter or leave the premises. Inside the city, hidden cameras are dotted along every road and alleyway.
In addition to the ground-level security protocols in Academy City, the satellite Orihime 1 (where the Tree Diagram supercomputer is located) and Hikoboshi II (a camera satellite and also a satellite laser-cannon) gathers detailed pictures of the area and relays it back to Earth.
The primary peacekeeping forces in Academy City are Judgment and Anti-Skill; these two groups are composed of trained students and faculty respectively which deal with crimes and conflicts with security. They are authorized to retrieve Information from surveillance equipment within Academy City, to check if there are any crimes occurring, in addition to their constant patrol duties.
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.

District Number / Functions/Specializations/Noted Locations
1 Where most of the city's administration is located
2 Training areas for Judgment and Anti-Skill
3 Accomodations for authorized outsiders (which also includes hotels, private pools, etc.)
4 Food-related facilities, including experimental crop growing
5 Mostly filled with universities and junior colleges
6 Recreational facilities, which also includes an amusement park
7 Middle and high schools, school dormitories, boarding houses, hospitals, the "Windowless Building" where Aleister Crowley is located
8 Mainly for the various teaching staff of the city
9 Industrial arts and fine arts schools
10 Reformatories, nuclear energy research facilities, the city's only cemetery
11 Goods transfer
12 Theology system schools
13 Kindergartens and primary schools
14 Accomodations and various other facilities for overseas students
15 A large district consisting of the city's major shopping district and mass communications facilities
16 Focuses on commerce
17 Railway cargo storage and organization, where Touma fought Accelerator to end the "Experiment"
18 Kirigaoka Girls' Academy and Nagatenjouki Academy
19 Uncertain; has been in a decline recently
20 Schools focused on raising athletic students along with their esper abilities
21 Dams for water storage
22 The smallest district in terms of surface area; this district is mainly for developing technology for an underground town in the face of land shortages in major cities
23 Airline companies and aeronautics and space development
[Synopsis]
The city for espers and science from the to aru universe.
[People of Interest]
Heaven canceller, frog faced doctor who has never lost a patient
The board of directors, apparant rulers of academy city
the seven level 5 espers, the strongest in academy city
[Places of Interest]
Heaven Canceller's Hospital in district 7
The several schools and their esper curriculum, where one can learn their psychic powers(mages who learn esper powers will kill themselves by bleeding to death when they try to cast spells)
There are several training facilities that have acces to gravity training and increased speed and strenght training, using these facilities costs 2000 zeni a day.