Stausee Mooserboden, Alpine reservoir in Kaprun, Austria

Stausee Mooserboden is an alpine reservoir in Kaprun, Austria, consisting of two artificial lakes sitting at roughly 2,040 meters altitude within Hohe Tauern National Park. The two basins are held by massive concrete dams, while the surrounding peaks rise above 3,000 meters.

The two lakes were built during the post-war years to generate hydroelectric power for the growing energy needs of Austria. Construction required thousands of workers to carve roads, tunnels and the two dams into the mountains.

The name Mooserboden refers to the mossy ground of these high alpine slopes. Between the two dams stands the Höhenburg rock, where the Ehrenmal, a 14-metre concrete monument by sculptor Josef Magnus, recalls the 161 workers who died during the power plant's construction from 1947 to 1955. A plaque added in 2003 also commemorates the 120 forced labourers who perished on the site between 1940 and 1945.

The reservoir is accessible only from June to October when shuttle buses and the Lärchwand inclined lift operate. The steep ascent through the mountainside climbs more than 430 meters and ends directly at the dam walls.

An on-site exhibition explains hydroelectric power generation through interactive models and displays. The MOBO 107 via ferrata lets climbers scale the concrete dam wall itself, secured to steel cables while looking straight down at the water.