In the beautiful forests of the Upper Engadine, the trees are mostly upright and are therefore actually nothing special. They're just soothingly beautiful. But what if they are about 30 m below the water surface of a lake? Then it's not exactly scary, but puzzling. Dating of upright underwater trees in Lake Sils and Lake Silvaplana raises the question of the history of these lakes anew. Significant, multi-phase movements with serious consequences for the landscape have taken place here. The real causes of these processes are still a mystery. The geologist Christian Schluechter takes us on a journey of discovery. National Park Lecture Series www.nationalpark.ch/naturama free entry Reservations are advantageous due to limited seats, please to: kultur@laudinella.ch or by phone 081 836 06 02 Protection concept of the Swiss National Park