Roxen is a lake of approximately 10,000 ha (95 km2) located in central Östergötland. The lake is flown by Motala Ström on the way from Vättern to Bråviken. Roxen is a relatively shallow lake with a maximum depth of about 7 meters.

The lake Roxen is a very large eutrophic lake located on the fault bridle that runs through Östergötland County north of Linköping. The northern beach is lined with forest countryside, while the south is bordered by the landscape's agricultural environment. The lake has a very diverse natural environment with headlands, islands, inserts, meadows, delta formations, open stone beaches and inlet environments. The lake's water catchment area, which is a significant part of Motala's streams total catchment area, is very large and consists mainly of the three large watercourses of Motala ströms main river, Svartån and Stångån. Roxen has a very rich fish and bird fauna and probably also a rich plant life.

Tillrinnande vattendrag och Roxens utlopp

Originating watercourses and Roxen's outlet Roxen's inflow is dominated largely by the three major inflows of Motala's main feeder, Svartån and Stångån. In addition to the lake, another fifteen smaller watercourses run where Kumlaån, Sviestadsån and Stjärnorpebäcken belong to the more influential ones. The three major watercourses, as well as the lake's outlet, are of great importance for the nature of the lake and as possible play areas for the majority of the lake's fish populations.