Mysterious and changeable natural phenomenon

Your tour takes you to a spectacular natural phenomenon in the Harz - the Blue Lake. On your hike, you first get acquainted with the Schornsteinberg. It got its name because the charcoal burning operation channeled the smoke gases through a groove in the rock. Step by step, you approach your highlight. After a few kilometers, you see it, the Blue Lake. In spring, it shines blue and clear, and by summer it suddenly turns dark green. After a short rest, you head back to the cave village of Rübeland.

HWN Stamp No.: 89