Chillon castle is situated at the most strategic place on Lake Geneva's northern shore. The western part of Switzerland's alps consist of two chains of 2000 to more than 4000 m [6500 to 13000 ft] high mountains, the Bernese Alps in the north and the Pennine Alps in the south of River Rhône. Lake Geneva, the Rhône valley and two pass roads over the Pennine Alps (Grand St. Bernard and Simplon) give access from Burgundy / France and western Switzerland to northern Italy. Chillon castle has been placed at the very point the foothills of the Bernese Alps fall steeply down to Lake Geneva leaving only a very narrow passage along its shores. The castle thus gave control over both road and lake passage on an important trade and military route.
