In the middle course of the Oise valley, rescue and preventive excavations have revealed 38 occupations ranging from the Late Hallstatt to the Late La Tène. Until 2002, large-scale soil stripping suggested the emergence of “isolated” or small-scale structures that have since evaded diagnostic trenches. Besides this majority of small farms, there are hamlets, villages, centralising sites and residences. Few constructions are recorded. On the one hand, erosion on the high ground has erased evidence. In addition, there are structures that leave little or no evidence on the ground. Also, some architecture (buildings without post holes in the walls) can be confused with attics and granaries. Traduction : John Lynch.