Upper-Sûre Lake is located in the northwestern part of the country. It was formed by the diversion of the river Sûre not far from the town of Esch-sur-Sûre known for its 10th-century castle. In this way, the largest water surface in the country was created, today a reservoir for water supply and electricity production. The area around the lake has been declared a protected area of the Upper Sûre Natural Park. Beautiful vegetation and an abundance of birds complete the pleasure of visitors who come here for canoeing, kayaking, and sailing.