Black Lake” in English, this body of water has a dark surface as it reflects the brooding rock around it.
The lake is served by a gondola, which takes only 12 minutes from Zermatt and has been shuttling between these points since 1954. At the Schwarzsee you’ll have the best vantage point for the Hörnligrat ridge on the Matterhorn, which is written into mountaineering lore.
If you’ve got the right equipment and training you can strike out on foot for that distant point from here.