La Castañeda was one of the most emblematic spaces in the history of Mexican psychiatry, founded by Porfirio Díaz on September 9, 1910, and its buildings and clinical records were inhabited by women and men of all social classes. However, there are other inhabitants who are rarely mentioned: children. This article aims to be a first approach to the rescue of the history of childhood in La Castañeda, their voices, stories, experiences in a space that represented for the inhabitants of Mexico City the entrance to hell, the great "Locopolis" of the City.