The trail begins before dawn outside Ushuaia, where a minivan slips through low clouds and the first teeth of the Fuegian Andes appear. By the time hikers step out, the forest smells of wet lichen and resin; the path climbs, narrows, then opens onto a ribbon of glacial runoff that dares you forward. The lagoon—emerald in name and color—sits like a bright wound in the valley, fed by the Ojo del Albino Glacier above. From the viewpoint at roughly 900 meters above sea level, the glacier displays plates of blue ice and moraine, a quiet, slow-motion drama of ice meeting rock.