area berlin conservation area directions environment environmental protection forest german germany integral nature reserve landscape nature nature protection area nature-sanctuary owl pictogram preserve area protected area protection reserve sign trees wooden sign birch birch forest birch tree haunted forest protective area recreation area spring spring forest tree wood woodland azure blue cascades croatia dams flow green lake lakes landcape moss mountains national park Plitvice rocks stones summer water waterfall armory army bricks building defend defense festung fortress hidden historic modlin park parks roofs tower walls war