Pollux (4,092 m) is a mountain in the Pennine Alps on the border between Valais, Switzerland and the Aosta Valley in Italy. It is the lower of a pair of twin peaks (Zwillinge), the other being Castor, named after the Gemini twins of Roman mythology. It is separated from Castor by a pass at 3,845 m (12,615 ft), named the Passo di Verra in Italian and the Zwillingsjoch in German. The peak is known as Monte Polluce in Italian.
The first ascent was by Jules Jacot from Geneva with guides Josef-Marie Perren and Peter Taugwalder (father) on August 1 (the Swiss national day) 1864. Their route was via the Schwartztor, a pass first crossed by John Ball and Gabriel Zumtaugwald in 1845. The impressive north ridge was first climbed by Captain John Percy Farrar (a future President of the Alpine Club) and Wylie Lloyd with guide Josef Pollinger on 18 August 1893.
Ascents are usually made from the Rifugio Ottorino Mezzalama (3,036 m), the Monte Rosa hut (2,795 m); if traversing the peaks via Pollux's north ridge, PD+, the Capanna Quintino Sella (3,585 m), and the Cesare Volante e Giorgio Rossi bivouac hut (3,850 m). The first winter and ski ascent of Pollux was by Dr Alfred von Martin and Karl Planck on 7 March 1913.