tags: Fels, Senckenberg Naturmuseum, museums, Frankfurt am Main, Germany, travel, nature, cities, image of the day, photography Fels. Senckenberg Naturmuseum, Frankfurt am Main, Germany. Image: GrrlScientist, 13 April 2010 [larger view] This is a close look at a large rock standing on the grassy traffic island in front of the Senckenberg Naturmuseum. The grain shows how tortured this rock was when it was still soft.