The Sill is a 35 km long river in Tyrol, Austria. It is a tributary to the Inn River, merging with it in Innsbruck. It flows through the Wipptal valley, on the north side of the Brenner Pass. For the Second World War frigate class, see River class frigate The Murray River in Australia A river is a large natural waterway. ... This article is about the Tyrol, the region in the eastern Alps. ... The Inn is a river in Switzerland, Austria and Germany. ... Innsbruck City Center Innsbruck and Nordkette from south // Geography Innsbruck is a city in western Austria, and the capital of the Tyrol province. ... The Wipptal is a valley extending along the Sill river southward from Innsbruck, Tyrol, Austria, where the Sill meets the larger Inn river, up to the Brenner pass (1,374 m) at the Austro-Italian border, one of the lowest passes across the central Alps. ... The Brenner Pass (Italian Passo del Brennero) is a mountain pass that creates a link through the Tyrolean Alps along the current border between the nations of Austria and Italy. ...