The north-west side of the central Monte Rosa massif, with its enormous ice slopes and seracs, constitutes the boundary and upper basin of the large Gorner Glacier, which descends towards Zermatt and merges with its nowadays much larger tributary, the "Grenzgletscher" (), right below the Monte Rosa Hut on the lower end of the visible western wing. The Grenzgletscher is an impressive glacier formation between the western wing of the mountain and Liskamm, a ridge on its southwestern side on the Swiss-Italian border. On the eastern side, in Italy, the mountain falls away in an almost vertical wall of granite and ice, the biggest in Europe, overlooking Macugnaga and several smaller glaciers.