Archaeologists have discovered a line of 170 man-made underwater stone cairns along the shores of Lake Constance in central Europe. These cairns, up to thirty meters in diameter and almost two meters high, are estimated to have been constructed around 5,000 years ago during the Neolithic period. The purpose of the cairns is still unknown, but possibilities include cultic activities, burial platforms, social gathering sites, or aids for fishing. The discovery of a piece of wood with primitive traces of human processing has provided clues for dating the monuments. The researchers plan to return to the lake to further examine these mysterious structures. The discovery of these cairns is significant as it was not known for large groups of pile dwellers to maintain connections outside of their settlements, suggesting a new revelation about the activities of ancient communities in the area. This discovery further adds to the understanding of the history and activities of early human communities in the region, which has previously been evidenced by the discovery of stone tools and hunting camps, suggesting that Mesolithic hunter gatherers frequented the area without settling. The location of the cairns along the lake’s shores and the finding of wood during excavation further adds to the mystery of the purpose and function of these structures.