Walk the 23km Aletschgletscher, a UNESCO World Heritage site and the longest glacier in the Alps. Day 1: cable car to Eggishorn (2,927m) for the view, gear check + crampon practice on the lower tongue. Day 2: roped-up traverse from Konkordiaplatz across the central icefall, lunch at Hollandiahütte, finish at Lötschenpass. Strong fitness + sure-footedness required; no prior mountaineering needed — guide handles ropes + crevasse work.