The Weisshorn is a major peak of Switzerland and the Alps, culminating at 4,506 metres above sea level. It is part of the Pennine Alps and is located between the valleys of Anniviers and Zermatt in the canton of Valais. In the latter valley, the Weisshorn is one of the many 4000ers surrounding Zermatt, with Monte Rosa and the Matterhorn. The Weisshorn was first climbed in 1861 from Randa by the Irish physicist John Tyndall, accompanied by the guides J.J. Bennen and Ulrich Wenger.