Construction workers got a surprise recently while laying a pipeline underneath Lake Lucerne in central Switzerland. On the lake floor they found the traces of a prehistoric village! This finally confirmed a long-standing theory among archaeologists, who believed that people had lived in the area thousands of years ago. But why were the traces of their home so deep within the lake? Across Switzerland there are about 500 pile dwelling sites, but these are normally found along the shorelines of lakes. And how do archaeologists manage to unravel prehistoric findings underwater? On this episode of The Swiss Connection podcast, we take a boat ride to get to the bottom of this mystery. While onboard, we meet a team of international experts and learn about an unusual technique using sound to map the depths of a lake.