The terrain of the department includes the Alpine Mont Blanc Range; the French Prealps of the Aravis Range, the Chablais, Bornes and Bauges Alps; and the peneplains of Genevois haut-savoyard and Albanais (known collectively as "L'Avant-pays savoyard"). Its mountainous terrain makes mountain passes important to trade and economic life. Some of the most important are the Col de la Forclaz (which connects Chamonix to the Canton of Valais) and the Mont Blanc Tunnel, linking Chamonix to Courmayeur in the Aosta Valley.