Augmented Reality, 3D virtual worlds, etc.: the technology has evolved tremendously and so has its application to the field of education. Digital technologies have advanced to the point, where we are reproducing digitally more and more aspects of our life. We have parallel worlds: on the one hand the real world, and on the other virtual worlds, that can in fact be linked to the real one. They have different properties, but they can enrich and complement each other. In this paper, we explore the possibilities and challenges of these parallel worlds for educational uses.