This bridge, Barbarabrücke, was a hidden treasure in the woods on the path to the Siebenbrunnen waterfall. It was impossible to cross this bridge without getting wet! For this hike, I walked six hours from the village of Lenk to the source of the waterfall and back. To me, sustainable travel is to preserve the original environment of a place so that the next person who visits it after you can experience the same beauty as you did.