Mettray Penal Colony, situated in the small village of Mettray, in the French département of Indre-et-Loire, just north of the city of Tours, was a private reformatory, without walls, opened in 1840 for the rehabilitation of young male delinquents aged between 6 and 21. At that time children and adolescents were normally imprisoned together with adults. Aspects of the progressive way in which the Colony was organised anticipated the English borstal system established at the beginning of the 20th century.
Frédéric-Auguste Demetz (1796–1873), a penal reformer and lawyer at the French Royal Court, together with the architect Guillaume-Abel Blouet (1795-1853), toured the United States together in 1836 to study American prison architecture and administration for the French government. Today Blouet is probably best known as the architect who completed the Arc de Triomphe in Paris. Upon Blouet's return to Paris he devoted himself to the reform of prison design and in 1838 was appointed Inspector General of French Prisons. Blouet believed in using architecture to realize social reform and together with Demetz worked on the design and layout of the buildings for the Colony which was initially directed by Demetz after its opening in July 1839. It was noted as being officially opened on 22 January 1840.
The layout of the Colony was characterised by a sense of order and community. From the entrance to the Colony a large central square, dominated symbolically by a chapel on one side, lies at the end of a long tree-lined avenue. The entrance to the square has the director's house on one side and the preparatory school, where the instructors were trained, on the other. Ten identical, three-storey pavilions are arranged on the two sides of the square. These were referred to as houses and were the places where the boys lived and worked. There were workshops on the ground floor where the boys who did not work in the fields learnt a trade. The first floor functioned as a dormitory at night, with the boys sleeping in hammocks, and as a refectory during the day time. The second floor contained a separate dormitory for the younger children.