The Jungfrau-Aletsch protected area (officially Swiss Alps Jungfrau-Aletsch) is located in south-western Switzerland between the cantons of Berne and Valais. It is a mountainous region in the easternmost side of the Bernese Alps, containing the northern wall of Jungfrau and Eiger, and the largest glaciated area in western Eurasia, comprising the Aletsch Glacier.