In Austria, the Danube runs to the north of the Alps, separating it from the majority of the Böhmerwald, although some small areas, such as the Dunkelsteiner Wald south of the Wachau, belong geologically to the Böhmerwald despite being south of the Danube. The Wienerwald near Vienna forms the north-eastern corner of the Alps, and here the Danube passes at its closest to the Alps (see Viennese Basin).