This map was compiled by The Detail using data we requested from the Northern Ireland Prison Service under Freedom of Information legislation. It shows the home postcode district of 4,605 of the 4,856 children who visited Northern Ireland's three prison sites during 2013. Nineteen postcode districts had fewer than five children visiting prisons last year. In these cases, we have withheld the exact number to prevent identification of individual children. An asterisk (*) is in place within the prison breakdown of the data where a number is less than five. A hash sign (#) is used for a number greater than or equal than five where giving this number would allow a number less than five to be calculated. Children missing from the map had an incomplete or no postcode recorded.