Fundación de Los Barrios el 4 de agosto de 1704 Historical milestone · Los Barrios, Campo de Gibraltar, Cádiz Image of Los Barrios, not of the place itself. Los Barrios was founded on 4 August 1704 by Spanish residents of Gibraltar who left the Rock after its British occupation; the municipality prospered especially during the reign of Charles III. 4 de agosto de 1704 Photo: georama (CC BY 3.0) What to see and do in Los Barrios