Salvatnet

Salvatnet is a lake in Namsos Municipality in Trøndelag county, Norway. With its deepest depth of , it is Norway's and Europe's second-deepest lake, after Hornindalsvatnet. Alternate sources give the depth as either (old manual method) or (modern echo sounding method) at the deepest point. The lake sits close to the Norwegian Sea, about above sea level at the surface and reaches to a depth of below sea level. It is a large lake with an area of , a volume of , and a shoreline that is around.

Salvatnet is a meromictic lake, meaning that the water is permanently stratified, often without oxygen in the lower depths (bottom water) due to density gradient and a lack of turnover. A meromictic lake often preserves records of the geologic past. The lower layer of the lake is highly saline and as a result denser than the higher levels of water. Other meromictic lakes in Norway; with old seawater in the lower depths include Botnvatnet, Kilevann, Rossfjordvatnet, Rørholtfjorden an arm of the lake Tokke, Rørhopvatnet, Tronstadvann, and Øvervatnet.