Aletschwald, Protected forest in Riederalp, Valais, Switzerland

Aletschwald is an old Swiss stone pine and larch forest on the north and northwest slopes of Moosfluh and Hohfluh, in the Valais municipality of Riederalp, between 1600 and 2200 metres above sea level. Its upper part has widely spaced pines and larches with dwarf shrubs and bogs; the denser lower western part also holds spruce.

The forest was designated a UNESCO World Heritage site in 2001 as part of the larger Jungfrau-Aletsch protected area. This recognition emphasized its importance for preserving Alpine ecology and mountain environments worldwide.

Since 1976 the Pro Natura Zentrum Aletsch has occupied Villa Cassel on the Riederfurka above the forest, with a multimedia exhibition on several floors open from mid-June to mid-October. A 300-species alpine garden adjoins the villa, showing the flora of the Aletsch area in bloom. The forest itself has been left unmanaged since 1933.

The forest is reachable by marked trails from Riederalp and other nearby villages throughout the year. Guided tours are offered during warmer months and provide helpful information about the woodland and its surroundings.

The forest's northern boundary was fixed at the edge of the Aletsch Glacier, so as the ice retreats the reserve keeps growing: from 250 hectares when protection began on 5 May 1933 to about 330 hectares in the 1990s. On the moraines the glacier has left behind, moss cushions and saxifrages give way to old Swiss stone pines within a short walk.