Leopoldberg forms the northeastern corner of the Alps. Alternating layers of marl (rich in carbonate) and sandstone form the parent rock. Unlike most of the mountains of the flysch zone (Upper Cretaceous and Tertiary periods), the Leopoldsberg has steep slopes due to the erosive power of the river Danube on one side and of a small creek on the other. This relief intensifies the differences in local climate and vegetation, which are provided by the borderline between Pannonic and Central European climates. The northern slope is covered with beech forests, the most common forest type of the Wienerwald.