Lucerne divers survey endangered prehistoric settlements in Lake Sempach

Archaeologists from the canton of Lucerne are systematically surveying prehistoric pile-dwelling settlements in Lake Sempach, where climate change and human activity threaten the remains, SRF reported.

Divers from a boat examine shallow waters off the town of Sursee, uncovering, photographing and measuring wooden piles buried beneath stones, aquatic plants and silt. A GPS buoy helps document the locations. The pile arrangements may allow researchers to reconstruct house plans and, in some cases, identify different stages of construction.

During one dive, underwater archaeologist Corinne Stäheli found a 10-centimetre bronze pin with a decorated head. The pin, which dates to the Neolithic period, was probably used to fasten clothing. Stäheli said it was a chance discovery: finding such a small object depends on searching in exactly the right spot. Divers have also found pottery fragments there.

Lucerne cantonal archaeologist Christian Auf der Maur said such finds were a bonus. The main aim is to gather basic archaeological data because little is known about the individual settlement sites in the canton’s lakes.

The remains are vulnerable when water levels are low. Waves can then affect the lakebed, and air may reach the wooden piles, causing them to decay. People standing in shallow water have also trampled or pulled out piles, Auf der Maur said. Depending on their condition, the sites may be protected with covers or barriers.