ArgumentFrom 1893 to 1909 when it definitely sunk into the glacier, the Mont-Blanc Observatory (MBO) struggled to find its scientific purpose. In this article, we use recent literature on the social characterization of place to analyze this struggle. Our first goal is to investigate where the observatory may fit in the laboratory-field dyad. We investigate various kinds of conceptual “borderlands” between these places and look at the networking activities between particular knowledge production sites. We argue that part observatory, part laboratory, (...) and part field station, the place of the MBO was “heterotopic” space in Foucault's sense. We then examine the social underpinnings that led to the foundation of this observatory in the context of French Third Republic at the turn of the century. Following some of the ways the MBO was connected to other scientific sites and surveying some of its visitors' scientific practices, we finally hint at the fact that some of these practices played a part in the emergence of a regime of science production that endured into the twentieth century (astrophysical aeronautical practices, spatial stations, polar exploration, etc.). (shrink)