Photo: Valery Shcherbina.
Riffelsee is an alpine lake above the town of Zermatt in the canton of Valais, Switzerland. It lies below the Riffelhorn at an elevation of 2757 m, and has a surface area of 0.45 ha. The lake can be reached from Rotenboden railway station (2815 m) on the Gornergratbahn mountain railway. Source: Wikipedia