Prisons are visible tokens of the failures of freedom and in a way the failures of education. Paradoxically, they are also a way of addressing those failures. This is the premise of this article, which emphasizes the value of social pedagogy and social education as alternatives to conventional educational practices. Conventional ways often jar with the circumstances in which members of the prison population live their lives while serving their sentences and afterwards. That is why we insist on the need to look for comprehensive educational responses that are methodologically plural and open to forward-looking pedagogical practices. First, penitentiary institutions must become ethically engaged in 'rehabilitating' prisoners for their civic rights and duties. Second, while prisons are an adverse, controversial environment for education, prisons have the obligation to foster full personal development for inmates and actively help inmates become autonomous and integrated into society. Lastly, the penitentiary system should expand its horizons to other environments and realities. It is a 'learning community' that cannot and should not be cut off from society. This must be recognized. Prisons have a job to do in social education. This is the setting in which the initiatives that the Spanish penitentiary system has promoted over the past few years have taken place. The initiatives are grouped into five major areas of action: action programmes, formal education and training, employment and job placement, leisure and culture, and sport. All these programmes have their own hallmarks of socio-pedagogical identity, in terms of principles and values, aims and objectives, methodologies, the target population and the partners involved.