This article builds on APREN-DO research project, which explores how secondary school teachers learn, using an inclusive research approach and visual and narrative methods. To this end, twenty-eight secondary school teachers created and narrated their learning cartographies, showing what, how, where, with whom, and with what they learn. This paper challenges traditional conceptions of learning (mainly cognitive or individual) and introduces the notion of learning ecosystems where intra-action is at the core of learning. It considers the (dis)continuous, non-linear, fragmented and fractal dimensions of learning made up of intra-actions between living beings, culture, and matter. It provides results on the learning characteristics of teachers, and the peculiarities of their significant ecosystems (professional, familial, and educational). It evidences that teachers' learning takes place everywhere, in every space, at every moment of their lives, with different people and the surrounding resources. We also highlight suggestions for improving teachers' professional development.