Local institutions can be effective tools in engaging environmental education. Especially, Environmental Education Facilities/Centres (EFF) have a high degree of relevance in the Eixo Atlântico Region (Galicia, Spain and North of Portugal). This study investigates the EEF's capacity to improve social involvement and impact. A multiple case study strategy was employed in which in-depth interviews were conducted with directors from 29 facilities in Eixo Atlântico. The research reveals a high level of EEF social impact, which was optimized when employing strong partnerships, when clearly-defining the sociocultural objectives of the educational program, and when the local population was actively involved.