This is the standard and best-documented route to Castor’s summit. It is a classic high-alpine snow and ice climb on the West Ridge, usually started from the Monte Rosa Hut. The route involves glacier travel, crevasse awareness, and a sustained ridge ascent with exposed sections. Conditions can vary significantly, especially on the upper ridge where snow quality and wind loading matter. The climb is generally considered less technical than many 4000 m peaks, but it still requires full alpine equipment and good route-finding. The descent is normally made by the same line and can be slow in poor conditions.