In the summer of 2017, a collectively-built mountain, the Mont Réel, emerged in Montréal, providing a gathering and performance place for the surrounding communities and an in-situ laboratory to experiment with urban (bio)diversity. It was conceived and constructed by Constructlab with many friends, colleagues and participants during the “ateliers collaboratives” workshop. It was supported by the Goethe-Institut Montreal in partnership with the Consulate général de France à Québec and the Université de Montréal.