The Monte Rosa chain, on the border with Switzerland, stretches from Col du Théodule to the Monte Moro Pass in the Anzasca Valley, and takes in a good number of peaks of over 4000 m. The best known of these are the Breithorn (4165m), Polluce (4092m), Castore (4228m), Lyskamm East (4527m) and West (4480m) and the Pyramide Vincent (4215m).

The most important glaciers include those of Felik, Indren and Verra, from which springs the Evançon Torrent in the Ayas Valley, and the glaciers of the Lys that feed the torrent of the same name that runs through the Gressoney Valley.

The valleys of the Monte Rosa chain, like many others in the Aosta Valley, are of glacial origin, and are thus characteristically U-shaped, narrow at the mouth before opening out to form wide green basins where broad-leaf, larch and fir woods give way to alpine grassland.

The presence of these large glaciers has allowed for the formation of numerous lakes, which are popular destinations with hikers. These include the Pinter Lakes, the Perrin Lake, the Blue Lake of Verra, the Palasinaz Lakes and the Frudière Lakes, all in the Ayas Valley, and, in the Gressoney Valley, the Salero Lakes and  the Nétschò Lakes. 

Easy to be reached, the Gabiet lake in Gressoney-La-Trinité and the Gover lake in Gressoney-Saint-Jean.

The Villa Lake at Challand-Saint-Victor,  in the Ayas valley, since 1982 has been a nature reserve where you can see the white waterlily growing wild, an extremely rare spectacle for the Aosta Valley.