At 4223m Castor, is located a kilometre southeast along the border from Pollux. Aside from its rocky south wall, the Castor is almost completely wrapped in in snow and ice. A bit harder than Pollux, Castor is still one of the simpler four-thousanders to climb. However, abrupt weather changes, crevasse dangers and considerable difficulties in orientation on the Breithorn Plateau must be taken into account. The normal climbing route starts at the Quintino Sella hut, goes up along the Felik Glacier to the pass of the same name, then runs along the narrow South-East ridge passing the foresummit (4,176 m) and finally reaching the 4,226 metres of the summit. This is done a 2 day itinerary from either the Ayas Guides Hut or the Quintino Sella Hut.