The archaeological research in the north urban sanctuary of Poseidonia aimed to further knowledge of the sacred landscape in its earliest phase, the one preceding the area’s present layout. Thus, the fieldwork focused on identifying the edges of the old excavation trenches in order to reach the earliest occupation levels that survived later interventions. An excavation area of c. 400 m2 was laid out in the south-western part of the sanctuary, inside which two trenches (SS. 242, 243) were opened a short distance apart, where the geophysical survey had revealed anomalies attributable to structures or interruptions in the regular conformation of the stratigraphy. The first trench (S. 242), the furthest north, measured 2 x 5 m and was c. 15 m from the base of the _Athenaion_ in correspondence with the space between the sixth and eight columns of the south side of the peristasis. The excavations exposed the southern margin of trench C, opened in the 1930s by A. Maiuri, which was emptied to a depth of c. 1.10 m revealing an archaic occupation surface at the bottom. To its south, once the surface soil was removed, a thick layer of travertine, both chippings and crushed, was uncovered. It can be attributed to the late 6th century B.C. and was used during a phase of reorganisation of the sanctuary, to obliterate the earlier remains and raise the floor level. This layer covered an accumulation of tiles and other objects flattened on a beaten earth surface, interpretable as the collapse of an archaic building that will be investigated next season. The finds included a “horned” type antefix datable to 580 B.C., fragments of Corinthian pottery datable to between the second and last quarter of the 6th century B.C., the arm from a statuette of an armed female, and bronze laminae and lumps, some of which presenting traces of burning. The second trench (S. 243), 3 x 6 m, was opened to the south of the first with the aim of finding the northern margin of the _plateia_ Be3 that separated the sanctuary from the agora. However, here the archaeological levels appear totally compromised by the planting and later removal of a row of Cyprus trees surrounding the sanctuary in the 1930s.