The border now encircles the Italian Domodossola valley, passing Gonda, Monte Leone, Bortelhorn, Helsenhorn, traversed by the Simplon Tunnel connecting Brig with Varzo, Grieshorn just south of Nufenen Pass, and forming the western border of Ticino runs across Marchhorn, Basodino, Pizzo Fiorera, Wandfluhhorn, Pizzo Quadro, Pizzo di Porcaresc, Pilone and descends below 1000 meters running across Centovalli along a stretch of the Melezza.