The article aims to reflect on the critical and heuristic potential of sociological research on the São Paulo prison system, carried out through the engagement of researchers in collectives and activities of Pastoral
Carcerária. The astronomical dimensions of the São Paulo prison system; its remarkable centrality in the conflict management mechanisms that guarantee the (re) production of the contemporary city; as well
as the various difficulties imposed by the prison administration on public scrutiny of the prison environment in general, and the practice of scientific research in particular, are the main justifications for this reflection. Throughout the text, the practical and analytical meanings of the work of different researchers / pastoral agents are exposed and discussed through a geological metaphor, asking about the characteristics and limits of the practices and knowledge that unfold in the underground, on the surface and at the top of the prison system.