Did large aggregation sites exist in Southern Scandinavia already around 6400 BC, during the Kongemose period? The preliminary results of a major excavation conducted during May-August 2020 suggest this. In Ljungaviken at Sölvesborg in Southern Sweden, over 50 well-preserved Mesolithic huts have been found within a limited area, under thick layers of sand and gyttja from the Littorina transgression. The huts lie at close distances to each other but do not overlap visibly. In a few huts, bone material is preserved, which together with the constructions indicate settlement during the winter season. Construction details of the huts also indicate that they have been used for several seasons.