Mährische Pforte
Upper Silesia is situated on the upper Oder River, north of the Eastern Sudetes mountain range and the Moravian Gate, which form the southern border with the historic Moravia region. Within the adjacent Silesian Beskids to the east, the Vistula River rises and turns eastwards, the Biała and Przemsza tributaries mark the eastern border with Lesser Poland. In the north, Upper Silesia borders on Greater Poland, and in the west on the Lower Silesian lands (the adjacent region around Wrocław also referred to as Middle Silesia).