MOOCs, as a phenomenon, have irrupted into the education arena in recent years. The "free" component is attracting loads of learners from all over the world, who are sometimes approaching the online realm for the first time. The Spanish National Distance Education University (UNED) has implemented its own MOOCs, in two editions up to now (March 2013, November 2014). This paper presents a description of what has been done and focuses especially in relevant issues to be considered and lessons learned from this pilot experience.