Grosse Staatsschleuse

The Grosse Staatsschleuse in Unterseen controls the flow of the Aare River as it exits Lake Thun. It features large, arched concrete gates that regulate water levels to prevent flooding downstream. In nineteen twenty-one, engineers finished this structure to replace earlier, less reliable timber dams. During the construction, workers discovered that the riverbed required massive steel pilings driven deep into the gravel to keep the locks stable against the constant pressure of the water pushing toward the capital city of Bern.