Discover the historical and faunistic heritage associated with the sunken blockhouses of the Pyla as well as the archaeological operations and underwater biological studies conducted by the GRAMASA. As part of the construction of the Atlantic Wall, the French coastline was divided into several sectors. GRAMASA’s mission is to study and advance knowledge on the defensive system of the Arcachon sector. A large part of the blockhouses built along this coastal strip, between Montalivet and the south of Mimizan, was part of the Bassin d'Arcachon support group. The research work carried out by the members of the association takes different forms: - Archaeological operations planned in collaboration with the DRASSM and the SRA; - Inventory and study of terrestrial and submarine structures; - Terrestrial and submarine mappingmarine; - Bibliographical and archival research.