On its 2,850-km journey through Europe, the Danube River connects very different landscapes. While it flows from Regensburg to Hofkirchen in broad arcs through the wide valley, it crosses the picturesque narrow valley between Hofkirchen in the Passau district to Aschach in Upper Austria and intersects the southern foothills of the Bavarian and Bohemian Forests. The resulting steep valley slopes are called "Leiten".
In the Protected Areas along the Danube between Hofkirchen in Bavaria and Aschach in Upper Austria, there are large semi-natural gorge and hillside mixed forests. These occupy an outstanding position within the cultural landscape of Central Europe, as no other comparable areas have been preserved within the entire European area of the Danube.
Due to the shape of the terrain, hot, dry rock areas lie side by side on the steep slopes with cool-moist valleys with springs, streams and rivulets. Here silicate rock and base-rich rock meet – extraordinary for the Bavarian Forest – creating an exceptional diversity of habitats. These conditions result in high biodiversity, which is expressed in a large number of species of plants, animals and mushrooms that make their home here. In addition, the area’s location on the Danube and proximity to the Inn and Ilz Rivers contribute to the occurrence of unique species and communities.