The region is bordered to the south by Lac du Bourget and extends to the north in the former Savoy province of Genevois. The median altitude varies from within the plain. Its easterly border at its most abrupt reaches more than at Semnoz, the final peak of the Bauges Mountains. The western border rises gently to slightly less than , which overhangs the Chautagne valley almost at (the left bank of the Rhone, north of Lac du Bourget). In clear weather, the Chartreuse Mountains above Chambéry are visible to the south; the Mandallaz and Salève are visible to the north, beyond which Gex and Geneva are visible. Various slopes of lesser elevation, the Bornes Massif (La Tournette, Dents de Lanfon, Parmelan), the Aravis Range, Faucigny, and the Voirons up to Mont Blanc outside Rumilly (located behind Bornes) are visible to the northeast.