Page Type Page Type: Mountain/Rock
Location Lat/Lon: 45.92281°N / 7.79336°E
Additional Information County: Valle d'Aosta
Activities Activities: Mountaineering, Trad Climbing, Ice Climbing, Mixed
Additional Information Elevation: 13864 ft / 4226 m
Sign the Climber's Log



Castore 4226 m - Castor in German - is one of the classic mountains of the Monte Rosa massif in the Pennine Alps. It is located on the border between Valle d'Aosta (Italy) and Valais (Switzerland), along the main alpine watershed running from Breithorn to Punta Dufour.  More in detail it is located between the Polluce, from which it is separated from the Passo di Verra 3845 m and the Western Lyskamm, from which it is separated from the Felikjoch 4061 m. Together with its neighbour Polluce - or Pollux - it forms the "Gemelli" or "Zwillinge" ( "the twins"),   as the locals call them. This particular form appears especially when "the twins" are observed from the Swiss side. Their names derive from the Greek mythology. Higher than Polluce, Castore is one of the 4000s most visited in the Alps and one of the favorite destinations for climbers: in good weather it is not difficult to count dozens of people on the top. Check here the complete list of the 82 alpine Fourthousanders and the 46 minor summits: Club4000

The 'Twins' and Breithorn from Allalinhorn 4027m
The 'Twins' and Breithorn from Allalinhorn 4027m


Castore become particularly famous also in reason of the transit of the "Ottorino Mezzalama" ski-mountaineering contest,  a big course with ski that starts from Teodulo (Cervinia) and ends in Gressoney, after having passed the Lyskamm Nose. 

Particularly inviting because very aesthetic and not too difficult is the access from the Refuge Quintino Sella, where it starts the Normal Route on the South-East ridge. Castore does not present a climb with great technical difficulties along this route: the small ridges to overcome to reach the summit are very funny,  though quite airy.  To this aesthetic snowy South-East ridge starting from the Felikjoch is opposed a steep ice slope facing North-West where it runs another frequently climbed route with access from the Colle del Breithorn. The Colle del Breithorn can be quickly approached both from the Testa Grigia, point of arrival of the Breuil-Cervinia cable car (Italy), and from the point of arrival of the Klein Matterhorn cable car.  Castore can be climbed directly by traversing to South-East across the Verra glacier for about 1,30  to 2 hours to get the base of the mountain,  then about a 45 minute push to the top.  

Castore North-West face
Castor & Pollux
Castore and Polluce from the Gornergrat









The NW route can be approached also from the Val d'Ayas across the Vallone di Verra with the huts Mezzalama and Guide della Val d'Ayas.

Il Castore (4226 m)
Castore from the Breithorn


Another classic route starts from the Monte Rosa hut up and over the Zwillingsgletscher to the border ridge and to the summit. This is a long hump over 6-8 hours one way. Because of crevasses it is not recommend as a solo route.


The first ascent of Castore was performed in 1861, August 23 by the two British alpinists F.W. Jacomb and W. Mathews with J.B. and M. Croz.

The name Castor and Pollux, or Gemini, comes from the Greek mythology and refers to the two twin deities called "Diòscuri", sons of Zeus. They were worshiped in the ancient Greece as protectors of sailors.

Getting There

Map of approaches to Castor
Map of the different approaches to Castore


Italian side 

There are three different starting points to climb Castore depending on the chosen itinerary.  The easiest route to summit Castore starts from Rifugio Quintino Sella 3585 m,  located on the italian side of the mountain. The route to reach the hut starts from Stafal 1825, in upper Valle Gressoney.

Getting to Stafal

The village of Stafal m. 1825, located in the high part of Valle di Gressoney, Aosta Valley can be reached from the A5 Motorway, exiting Pont St Martin, then following the Valle di Gressoney until the end of the road.

From Stafal m. 1825 to Rifugio Quintino Sella m 3585

From the parking area a cable car leads 300 meters further up, where a chair lift by a long run leads up to Passo di Bettaforca m 2720. Here take the obvious path n. 9 to the Quintino Sella shelter, rising on the crest and getting quickly to the Bettolina Pass m. 2905. From here carry on the wide crest to the junction with the path coming from Pian di Verra. Follow the yellow marks, climb up some easy rocks, then follow the final airy ridge, equipped with fixed ropes, leading to the terrace on which is located the Rifugio Quintino Sella m. 3585.

Verra Glacier annotated view
Verra Glacier annotated view

Another Normal route to summit Castore starts from Rifugio Guide del Cervino m. 3480, located near the upper station of Testa Grigia cable-car, starting from Breuil-Cervinia.

Getting to Breuil-Cervinia

Breuil – Cervinia is a major mountain resort, located at the end of  the Valtournanche, Aosta Valley. Can be reached from the A5 Motorway, exiting Châtillon/Saint-Vincent, then following the Valtournanche.   Public transportation is easy to arrange.    Getting to Champoluc 

Another route starts from Rifugio Guide d'Ayas across Rifugio Mezzalama. The route to reach this huts starts from  St. Jacques, a hamlet of Champoluc in Valle d'Ayas, Aosta Valley.The village of  Champoluc can be reached from the A5 Motorway, exiting Pont St Martin, then following the Valle di Gressoney until the end of the road. 


Castore and Punta Perazzi
Castore and Punta Perazzi seen from Ref. Mezzalama


Swiss side 

From the Monte Rosa Hut 

You reach the hut from the station Rotenboden (Gornergrat cable car) over the Gornerglacier in 2 - 2,5 h, 200hm up and down. The way over the glacier is partly marked by poles. From the station Rotenboden, you choose the way with S-direction to the ridge saddle in the E of the Riffelhorn (signs). After a few 100 meters, the way goes up over the Gornerglacier to the E and slightly down to the S-flank of the Gorner-ridge. You reach the Grenzglaicer and traverse it to the S till you reach the E-side of the Grenzglacier. You climb up on the glacier below the hut. You reach via the moraine in short zigzag (100hm).  You can also come from the station Stockhorn. You pass the Stockhorn in 30 min. to the E to the Stockhornpass and traverse the Gornerglacier at the foot of the Nordend (NW). Then you go at the left side down and along the Monte-Rosa-Glacierbreak and the rocks. You reach the edge on about 3120m (pole). You go up slightly on the S-side and traverse the middle tongue of the Monte-Rosa-glacier to the Unteren Plattje and the hut (2-3h) 

Castor (13864 ft / 4226 m) & Pollux (13425 ft / 4092m)
Castor 4226 m and Pollux 4092 m


The Klein Matterhorn Cable Car station can be reached by taking the Cable Car all the way from Zermatt or one can hike up to it from the Gandegg hut in about a 1/2 to 1 hour walk. One could also stay at the Hotel Schwarzsee which is furter away than Gandegg at about 1-1/2 hours hike.

Castore - Normal route
Castore - Normal route


Normal routes

- Castore SE Ridge Normal route 

Difficulty: Alpine F+ / Difference in level: 640 m. from Rifugio Quintino Sella / Exposure: SE / First ascent: William Mathews and F.W. Jacomb with the guides J.B. Croz and Michel Croz 23- august 1861

A fine route - entirely glacial - without particular technical difficulty, but the ridge is airy and sharp and it should not be underestimated


Climbers on the upper ridge up to Castor, 4226m.
Climbers on the SE ridge up to Castore
castor's summit ridge coming...
The summit ridge (route from Ref. Sella)


Castore - Normal route
Castore - Normal route


Castore WNW Flank

Difficulty: Alpine PD+ / Exposure: WNW

It's the second normal route, a little more demanding than the previous route. The final ascent is made from the Zwillingsjoch, a 3848 m high pass on the Western side of Castore. As previously told the Zwillingsjoch may be approached from four different starting points:

- from the Rifugio Guide del Cervino on Testa Grigia cable-car upper station (Italy, Cervinia)

- from the Klein Matterhorn station 3883 m on the Swiss side of the border with Italy (Switzerland, Zermatt)

- from the Rifugio Guide d'Ayas (Italy)

- from the Monterosa Hut (Switzerland) -  it's the longest approach

Final crest to Castor summit 4223m
Final crest to Castore
Northwest face of Castor
Northwest face of Castor


Other routes

- South wall and SW ridge - AD

- NW wall of SW spur - TD/ED


Il CastoreRidge of Castor



Italian side

Refuge Sella
Refuge Quintino Sella

 Rifugio Quintino Sella m. 3585 - Phone +39 0125 366113 Mob +39 348 8107793 E-mail:

Situation: Felik Glacier shore 

Open: from middle June to middle September - Size: 140 persons + 25 in the winter shelter

Owner: CAI Sez. Biella - Guardian: Ezio Cassina 

Getting there: From Gressoney-la-Trinité reach Stafal hamlet 1825 m (5 km from the capital). Wide parking lot. From the parking area a cable car leads 300 meters further up, where a chair lift by a long run leads up to Passo di Bettaforca m 2720. Here take the obvious path n. 9 to the Quintino Sella shelter, rising on the crest and getting quickly to the Bettolina Pass m. 2905. From here carry on the wide crest to the junction with the path coming from Pian di Verra. Follow the yellow marks, climb up some easy rocks, then follow the final airy ridge, equipped with fixed ropes, leading to the terrace on which is located the Rifugio Quintino Sella m. 3585.


The refuge
Refuge Mezzalama

 Rifugio Mezzalama 3004 m - Phone: 0039-0125-307226 - e mail

Situation: Ghiacciaio di Verra

Open: summer  - Size: 36 persons + 20 persons in the winter shelter: 20 persons 

Owner: C.A.I. Torino  - Guardian:  Maurizio Piffari (mobile 328 2128835) 

Getting there - From Champoluc, hamlet St. Jacques. We leave the car in the church square and continue on foot for a few minutes to the Blanchard district. Here the signpost indicate the direction of the path n ° 7. After a small bridge, the trail leads through the woods, passes a clearing and into the wood again until converging with the dirt road (closed to vehicles) coming from Saint-Jacques. Cross the Pian di Verra Inferiore, after which the signposts indicate the Blue Lake and on the right Rifugio Mezzalama and Rifugio Guide Val d'Ayas. After crossing the bridge, we follow the path which cuts the road then along the river we enter a valley that leads to the Upper Pian di Verra. Shortly before, indicated by two signs, the trail branches off to the left and up the steep slope that forms the other side of the moraine. The trail passes along the edge of the moraine in sight of the hut, then it appears also the higher Rifugio Guide Val d'Ayas. Yet following the moraine we reach the hut.

The refuge
Refuge "Guide d'Ayas"

Rifugio Guide d'Ayas 3420 m - Phone: 0039-0125308083 Email:

Situation: Lambronecca spur

Open: from July to September  - Size: 85 persons + 16 persons in the winter shelter

Guardian: Guide di Champoluc e Val d'Ayas 

Getting there - Same approach as for Rifugio Mezzalama, then continue towards a side-tongue of the Grande Ghiacciaio di Verra. Cross the glacier and take the path on stony ground again. With the help of some footbridges and fixed ropes, the path overcomes the rocky promontory on which the refuge is located 4.30-5.30. Alternatively from Saint Jacques you can get on with an authorized taxi at Piani di Verra and for the previous access to the shelter


Swiss side


Monterosa hut.
Monterosa Hut

Monte Rosa Hütte 2883 m - Phone: +41-279672115 Email:

Situation: Grenzgletscher

Open: from mid-March to mid-May and from mid-June to mid-September -  Size: 120 persons + 28 persons in the winter shelter

Owner: Swiss Alpine Club 

On the Grenz Glacier
On the Grenz Glacier

Getting there - Summer: from Zermatt take the Gornergrat train to Rotemboden 2815 m. From here take the path to the Gornergletscher, marked with poles, small flags, white and blue stamps, fixed ropes in some stretches. You cross the glacier and pass on the Grenzgletscher, then you head to the Untere Plattje morain and climb it to get the refuge. 2,30-3 h. Winter: as Monte Rosa Hütte can also be reached from Stockhorn, where you arrive by the train to Gornergrat and then by the cableway to Hohalligrat and then by the same Stockhorn. And you can also cross the ridge to the Gornergrat. Once at the Stockhorn pass, continue towards Plattje Unteren, reaching the refuge in about three hours. An additional possibility is to start from the Furi locality through the Gorner glacier: an itinerary of about 9 kilometers not marked and must be built by trained people, preferably on a rope. The difference in height is 940 meters, the time is 4 hours.

When To Climb

Mountaineering. from June to September (crowded in July and August) 

Ski-mountaineering: Good at all times except when there are heavy snow conditions can cause local avalanches.

Castore - Normal route
Castore - Normal route
On the Breithorn plateau
On the Breithorn plateau
Early morning on castor ridge.
Early morning on Castore
Climbers on Castor (13864 ft / 4226 m)
Climbers on Castore


"Il grande libro dei 4000" by Marco Romelli and Valentino Cividini - Idea Montagna ed.

"Tutti i 4000" - L'aria sottile dell'alta quota - Club4000/CAI Torino

“4000 delle Alpi” by Richard Goedeke - Ed. Libris “Monte Rosa” by Gino Buscaini – Collana Guide dei Monti d'Italia C.A.I.-T.C.I. - Maps "Breuil/Cervinia-Zermatt" Kompass map 1:50.000 "Cervino-Matterhorn e Monte Rosa" n. 5 - Istituto Geografico Centrale 1:50.000

Meteo forecast

- Meteo Valle d'Aosta

- Meteo Switzerland

External Links

- Zermatt - Alagna - Castor at - images, routes, coordinates and more information about the highest peaks of the Alps



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