Panoramic view to the volcanoes of the Siebengebirge mountains (Photo: Tobias Schorr)

The Oelberg volcano in the Siebengebirge mountains (Photo: Tobias Schorr)

The tower of the castle at the Drachenfels in the Siebengebirge area. (Photo: Tobias Schorr)

View to the famous lava dome Drachenfels ("Dragon rock") of the Siebengebirge mountains. This lava dome is mainly formed by trahitic rocks. (Photo: Tobias Schorr)

View for the Siebengebirge mountains on the Rhine river (Photo: Tobias Schorr)

View from the summit of Oelberg volcano on the other volcanoes of the Siebengebirge area. (Photo: Tobias Schorr)