Thirty-four years ago there appeared in the Proceedings of the Prehistoric Society the third and final paper in a series reporting the research of Eric Higgs and his colleagues into the climate, environment, and Stone Age record of north-west Greece (Higgs et al. 1967). This paper discussed two limestone rockshelters, Kastritsa and Asprochaliko, comparatively in what is now a classic example of site catchment analysis. Kastritsa, in the Pamvotis lake basin, and Asprochaliko, some 35 km away in the Louros river valley (Fig. 1), were destined to become famous, not only for being amongst the first sites in Greece to yield stratified Palaeolithic deposits, but also for the methodological and interpretative issues raised by their archaeological records. The ideas presented in the 1967 paper aroused considerable debate and controversy regarding when and during which seasons the sites were used and whether they were complementary parts of the region's Upper Palaeolithic settlement system (Higgs et al. 1967; Bailey et al. 1983; Bailey 1997a; Green 1997). The essential assumption underlying Higgs' original hypothesis was that some of the strata recovered from these sites were contemporaneous. In recent years the upper part of Kastritsa (strata 1 & 3) has also been considered to be partly coeval with two of the rockshelters in the Voidomatis river valley, namely Klithi and Megalakkos (Fig. 1).