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.

The Jungfrau-Aletsch protected area is the first World Natural Heritage site in the Alps; it was inscribed in 2001.

The summit ridge separating the cantons of Valais and Bern is the main watershed of Europe.

Glaciers and barren rock constitute 80% of the area; 6% is forested, 5.2% is alpine meadow, and 8% is scrub.

The growing period decreases with altitude, but there are 529 species of phanerogams and pteridophytes above the tree line.

Characteristic species are the Swiss Pine (Pinus Cembra) and the Norway Spruce (Picea abies) on the north and south side respectively.

The zone directly above the tree line forms a girdle of moorland vegetation and Alpine grassland.

On the north side visitors are only able to visit the site via the Jungfrau railway which leads to the Jungfraujoch.

The Aletsch ecological centre in Riederalp is run by Pro Natura functions as a visitor center.