The Kastrakli Reserve was created to protect the extraordinary find of black pine. Most of the trees are over 200 years old, and they grow straight upon the steep rocks – this is a spectacle that can not be seen anywhere else. The reserve has a deep picturesque gorge cut across by the Kastrakli River. The animal world is identical to the one of the Devin River, because the distance between them is just a kilometer or two, all covered with a fairy meadow called Kastrakli. Primitive flint tools from the Stone Age have been discovered here.