The bird reserve Oberes Donautal is one of the most important habitats for endangered birds such as the black stork, eagle owl or the wasp buzzard.
The 924 ha big European bird reserve "Oberes Donau- und Aschachtal" consists of two totally different parts: The Danube valley with its steep slopes between the border near Passau and Aschach and the ravines of the small river Aschach between Waizenkirchen and Hartkirchen.
The landscape of the bird reserve is formed by ravine forests and rocky slopes. In the flat hillsides dry and wet slope and ravine forests, oaks and beech trees move to mixed forests.
Besides, heaps of rubble and impressive rock formations can be found near the Schlögener Schlinge.
Some rare fish species live in this part of the Danube. Birds that are protected by the reserve are the black stork, the wasp buzzard, the eagle owl and other ones.