Besso (3667 m) is a mountain in the Pennine Alps in the Swiss canton of Valais. The name Besso means 'twins' in the dialect of the Val d'Hérens and refers to the twin summits of the mountain. The first ascent of the mountain was probably made by the guides J. B. Epinay and J. Vianin in 1862. The classic route on the mountain – the south-west ridge (PD+) – was, according to Collomb, 'possibly' first climbed by R. L. G. Irving and party in 1906. The Mountet hut (2,886 m) is used for the normal route, which is known as the 'Ladies' Route'.