The reservoir may be man-made, but the surrounding scenery has retained all its natural grandeur. The slopes to the west lead up to two of the valley’s mightiest glaciers, the Allalin and the Schwarzberg, which adorn the slopes of the Allalinhorn and neighbouring 4,000-metre peaks. At the southern tip of the lake, a trail leads up to the Monte Moro Pass on the border with Italy, marked by a golden statue of the Madonna.
At the crest of the dam, the friendly restaurant provides a handy stop for refreshments before or after the walk. The visitor centre offers an interesting insight into this innovative green energy scheme. The reservoir can hold 100 million cubic metres of water. Hydroelectric power stations further down the valley can generate nearly enough electricity for all the households in Valais. Thanks to the Mattmark and about 40 other dams in Valais, about 30 per cent of all hydropower in Switzerland is generated in this one canton alone.
However, construction of the dam took a heavy human toll. On 30 August 1965, part of the Allalin Glacier high above the construction site detached. About 2 million cubic metres of rock and ice came crashing down, burying the canteen and staff accommodation under up to 50 metres of debris. In all, 88 workers lost their lives.
Today, the valley is once again a place of tranquillity. Walkers have a good chance of spotting local wildlife along the trails around the reservoir: bring binoculars as well as a hand lens to admire local wild flowers.
For all hikes:
For mountain hikes:
For high-altitude hikes:
For certain hikes: