From Wikipedia, the free Encyclopedia: The Puster Valley (Italian: Val Pusteria [ˈval pusteˈriːa]; German: Pustertal, Ladin: Val de Puster) is one of the largest longitudinal valleys in the Alps that runs in an east-west direction between Lienz in East Tyrol, Austria, and Mühlbach near Brixen in South Tyrol, Italy. The South Tyrolean municipalities of the Puster Valley constitute the Puster Valley district. The Puster Valley is located in the western part of the Periadriatic Seam, which separates the Southern Limestone Alps from the Central Eastern Alps, as well as most of the limestone Alps from the central gneiss and slate peaks of the range's central section. East of Sillian, the Puster Valley leaves the Peradriatic Line (which moves into the Gail valley) and turns to the northeast towards Lienz. Half of the valley drains to the west to the Adriatic via the Adige river; the other half drains to the east to the Black Sea via the Danube. The watershed lies in the shallow valley floor called Toblacher Feld (Conca di Dobbiaco). The Rienz river flows westwards through the Puster Valley and the Drau river flows eastwards into East Tyrol. The eastern part of the valley on the upper Drava is called Upper Puster Valley.