The historical study of routes has long remained confined to the great Roman roads, to the modern royal roads and to the medieval pilgrimage routes. For fifteen years, the French school of Archaeogeography has revisited this research field in great depth, following the first intuitions of the archaeologist Eric Vion. The innovative idea ‒ at least because it leads to a questioning of our methods ‒ is to consider the current road network as the starting point of the analysis. It is the true object of research for the historianarchaeologist because it represents a solid legacy whose logic one must unravel. Because this story is closely integrated with urban, political and economic matters, the study of this inherited road network represents a precious reading key to understanding the history of the territories in the longue durée. In the frame of this paper, we propose to recall these methodological advances and to present a case study in Brittany, around the small town of châteaugiron. By this example, we want to show that the archaeogeographical analysis and interpretation offer a scientific narrative based on the paradigms of complexity and resilience to contemporary societies in charge of our territories.