Allalinhorn, Mountain summit in Valais, Switzerland

The Allalinhorn is a 4,027 m summit in the Pennine Alps of Valais, Switzerland, standing in the Mischabel range between the Saastal and Mattertal valleys, about seven kilometres south-southwest of Saas-Fee. Four glaciers surround it: the Feegletscher to the north, the Hohlaubgletscher to the northeast, the Allalingletscher to the southeast and the Mellichgletscher to the southwest. Four ridges run toward the summit, but except for the eastern Hohlaubgrat they disappear under a thick ice cap near the top.

Heinrich Michaelis crossed the Allalin Pass in 1828, opening the route to the southwest ridge. On 28 August 1856 Edward Levi Ames, a London barrister, reached the summit with Franz Andenmatten and a guide of the Imseng family from Saas-Grund. The northwest ridge, today's normal route, was first climbed on 1 August 1860 by Andenmatten with Sir Leslie Stephen and others.

The peak stands near Saas Fee, where mountaineers have long followed traditional routes that connect climbers to the high alpine environment in ways passed down through generations. Local guides and climbers maintain these pathways as part of how the region's mountain culture functions.

The Metro Alpin funicular ends at Mittelallalin station at 3,457 m, leaving about 500 vertical metres to the summit by the normal route, the WNW ridge (Grade F). The climb crosses the Feejoch and passes below the séracs of the north face, so crevasses are a real hazard; inexperienced climbers should go with a mountain guide or have crevasse rescue training.

Since winter, the summit is illuminated at night during the winter season, a detail visible from Saas-Fee. The mountain is surrounded by four glaciers: the Fee, Hohlaub, Allalin and Mellich glaciers. The name's stress on the final syllable points to a pre-German origin, and in 1840 Christian Moritz Engelhardt linked it to Arabic ala ain, 'at the spring'.