Mesolithic site of Paliwodzizna in northern Poland revealed contacts with Scandinavia were as early as 7-6000 BC. Archaeologists revealed remains of stone structures with hearths, walls, pavements with analogical ones known from Swedish and Norwegian sites. Among the finds are also geometric flint tools and blades that were mounted into handles or formed the points of arrows or harpoons.
Similar artefacts are known from other archaeological sites from Poland, where they have been discovered as single or multiple finds within structures that were considered as foreign culture influence. Discoveries from Paliwodzizna form another evidence for contacts between areas of Central and North Poland and Scandinavia in the Mesolithic. The archaeologists do not know yet what purpose did the discovered structures have but suspect that it might have been either connected with cult rituals (indicated by lack of pottery, and discovery of lumps of ochre) or production of tar from birch bark (indicated by finds of tar-like substance on unearthed stones).
(after Nauka w Polsce & G. Osipowicz)