As I wrote in a previous post, Harz region has been born from a sea bottom several hundreds of millions years ago. The remains of seashells and other marine animals have piled up and turned into a thick limestone layer which found its way out to the surface. An old quarry can be seen left exposed at the side of the road near Wernigerode, a beautiful city in the north of Harz. In the immediate vicinity of the quarry one can see an old defense tower dated back to the 11th century. At a closer look at the walls of this tower we could see small round seashells as a prove of the former marine origins of its construction bricks:

Small rounded seashell fossils from 285 million years ago in an old limestone quarry