Hohenbol in early springtime, Middle Swabian Alb. The mountain is one of the volcanos within the Urach-Kirchheimer Vulkangebiet. The mountain with the castle on top is the Teckberg, also of volcanic origin. There is evidence of 356 volcanos of the type “Schwäbischer Vulkan”, all extinct in Upper Miocene; most of them throwing up basaltic tuff, which tended to being stuck in the volcanic pipe.