Description "Voyages de l'infiniment grand à l'infiniment petit" ("Journeys from the infinitely large to the infinitely small") is a French Massive Online Open Course aimed at promoting nuclear and particle physics as well as astrophysics and cosmology to high-school teachers and pupils. Designed by an editorial team of physicists from CNRS and CEA and edited with the pedagogical and technical support from Ecole Polytechnique, this MOOC is composed of 4 courses (Physics of the infinitely small, physics of the infinitely large, The links between the two, The connections with everyday life), consisting in 10 modules of 10 minutes each, and a dozen of speakers have contributed in the writing of the modules. The MOOC students can follow the 4 courses and test their knowledge through a series of quizzes on the Coursera platform. This MOOC aims at providing an overview of high-energy physics to interested students with a high-school level in physics, and also at giving video and text resources to high-school teachers willing to include high-energy physics in their lectures.