The transition between Solutrense and Magdalenian is a widely discussed issue in both French and mainland territories. In view of the difficulty of establishing continuity or discontinuity between the two cultures, and above all the identification and characterisation of Badeguliense in France, a crucible of theories has been created about the end of the Solutrense and the origin of the Peninsular Magdalenian. The characterisation of this possible new horizon, which is intended to be introduced in some stratigraphies of moderately excavated fields with a clear rupturistic sympathy, creates some confusion in determining a precise paleoclimatic and chronological context for these industries. The assignment of final Solutrense levels (Caldas XIV and 3-6; La Riera 9-14), and also from the classical lower Magdalenian (Caldas XIII), to a Cantabrian Badeguliense, Solutrense Final, Arcaico Magdalenian or Magdalenian lower is not a minor or terminological issue. By contrast, the identification of either horizon is still subject to chronological comparisons, to the study of isolated levels or to the identification of lytic elements and bone isolated from the archaeological register, which are not always present in their entirety (raclettes, local raw materials, non-laminar techniques and pseudo-excisa technique). This work focuses on the study of deposits at the end of Solutrense and their relationship with the oldest Magdalenian levels, in the stratigraphic context of the Nalón valley (La Paloma, Entrefoces, and Las Caldas). Particular attention is paid to the broad sequence of the Caldas cave (levels XI to XIII, XIV and 3 to 6), where the occupations of the final Solutrense and the lower Magdalenian are held in rooms I and II of the cavity, and for which 26 14C figures are available (AMS and 14C conventional).