Like the two other tunnels passing below the Gotthard, the Gotthard Base Tunnel connects two Alpine valleys across the Saint-Gotthard Massif: the "Urner Reusstal" in the canton of Uri, in which flows the river Reuss, and the Valle Leventina, the largest valley in the canton of Ticino, in which the river Ticino flows. Unlike most other tunnels, the Gotthard Base Tunnel passes under several distinct mountain massifs, two of them being major subranges of the Alps, the Glarus Alps and the Saint-Gotthard Massif, with the valley of the Anterior Rhine, the Surselva in the canton of Graubünden, between them. The tunnel passes under these two ranges more than below the Chrüzlistock () and the Piz Vatgira (, near the Lukmanier Pass). While the cantons of Uri and Ticino are part of the German- and Italian-speaking areas of Switzerland respectively, the Surselva is mainly Romansh-speaking.