Döderhultarns namnteckning

Eckern is a long, narrow lake, 3.5 kilometers long and widest at 350 meters, and at its narrowest point, known as the "Smale neck," it is 100 meters wide. The lake has been regulated since the 1950s and serves as a reservoir for the municipality's water supply. The water level fluctuates between 37.1 and 38.8 meters above sea level.

During low water levels, the inscription "DÖDERHULTAREN 1921" can be seen on Eckern's shore, 1 kilometer north of Sandvik. According to hearsay, it was a stonecutter from Vånevik who did the work. The lake's surface was then about 2 meters lower. The inscription is 120 centimeters long and 25 centimeters high.