Yngaren, Lake in Södermanland County, Sweden

Yngaren is a lake in Södermanland that stretches across three municipalities and connects to the Baltic Sea through the Nyköpingsån river system. The water reaches depths of around 20 meters in some areas and forms a significant body of water in the region.

Yngaren was lowered by two metres in 1858, when its surface area shrank considerably; before that it was both deeper and larger. The lake lies on the Södermanland lake plateau and is drained by Nyköpingsån, called Åkforsån at its inflow and Skräddartorpsån at its outflow. Its name comes from the Indo-European root "engh-", meaning narrow.

The name Yngaren comes from the Indo-European root "engh-", meaning narrow, as in German "eng". The shore is dotted with settlements: Björkvik in Katrineholm, Bettna in Flen, and Stigtomta and Vrena in Nyköping. Olsholmen, one of the lake's islets, held a croft until the 1930s.

Yngaren supplies drinking water to Nyköping and Oxelösund and most of rural southern Södermanland, so boating and shore activity should respect that. Public bathing spots include Bettnabadet in Flen Municipality, with jetties, and Bärsta and Harhålet in Nyköping; algal blooms can occur at Bettnabadet. The lake freezes over in normal winters but can stay ice-free for long spells in mild weather.

Yngaren supplies drinking water to Nyköping and Oxelösund and to most of rural southern Södermanland. Its water is clean and nutrient-rich, and the lake is deep for the region, reaching 19.7 metres. The name comes from an Indo-European root "engh-", meaning narrow, as in German "eng".