 Located in the Danube basin, the ancient Roman province Pannonia Superior, Austria bordered on the Kingdom of Hungary beyond the March and Leitha rivers in the east.In the south it was confined by the Duchy of Styria, with the border at the historic Semmering Pass, while in the north the Bohemian Forest and the Thaya river marked the border with Bohemia and Moravia.In the west, the Upper Austrian part bordered on the Bavarian stem duchy.