Rien is a lake in the municipality of Røros in Trøndelag county, Norway. The lake is located near the headwaters of the river Glomma, only about west of the border with Sweden. The water flows out through the river Glomma and heads a short distance south, into the large lake Aursunden. The village of Brekken lies about south of the lake and the town of Røros lies about to the southwest. See also List of lakes in Norway References Røros Lakes of Trøndelag