Twenty-three kilometres of ice flowing down from Konkordiaplatz like a frozen river, its dark medial moraines drawn along it like lane markings — the longest glacier in the Alps and the core of the region's UNESCO natural site. Cable cars from Riederalp, Bettmeralp and Fiescheralp reach the viewpoints in half an hour, with trails running along the rim. The nearby Aletsch forest holds Swiss stone pines close to a thousand years old.