As an example of Open Authority (Phillips, 2013), the Art Maps application epitomises an upcoming tendency in the broader museum field – that of an open-source platform inviting contributions from users around the world, while retaining the institution’s authority. Developed by Tate and the Horizon Digital Research Institute between 2012 and 2014, Art Maps crowd-sources geographical data to map the gallery’s collection, and allows users to suggest multiple locations for each artwork in recognition of the subjective nature of the relation between art and place, and of the personal experience each user might have of a specific location. As the cartographic effort is entrusted to users rather than being ‘imposed from above’ (Harley 1989) by the institution, the power inherent to map production is democratically shared among all users, albeit moderated and eventually sanctioned by Tate. Herein we explore how users accessing Art Maps outside the gallery might be in some ways reframing their own environs, defining a contract with the gallery on the lines of that between performers and spectators in mixed reality games (Benford et al., 2006), which transposes not only the collection but the very attitude associated with contemplative engagement with art, to the outside world.