During the 1860s, Berlin’s exterior physiognomy transformed radically. The city eroded the surrounding rural areas, and the frontiers of the old city centre were abolished. These transformations led to the disappearance of the visible frontiers that once demarcated the limits of the old residential Prussian city. In this context, the description of the clinical picture of agoraphobia by the Berlin psychiatrist Carl Westphal in 1872 marked a turning point, not only in psychiatric theories on anxiety but also in the conceptualization of our experience of space. In this paper, the authors trace the emergence of a new psychology-neurology episteme during the last third of the nineteenth century; and they argue that such an episteme became possible once the relations between anxiety and modern city-scape had been clearly articulated.