Panoramic view of the Silvretta reservoir from N direction. Located at 2030 m asl. at the Bielerhöhe, a mountain pass between the provinces of Vorarlberg and Tyrol, the reservoir was constructed in the period between 1938 and 1951. Part of the work was done by forced labourers and prisoners of war. The reservoir collects the water from the valleys in the central background (Ochsental on the left side and Klostertal on the right side) and, through a tunnel, from the Bieltal shown in the left background.