The sheer height and wacky “double curvature” make you lose your balance just looking at this dam wall when you arrive for a surprise. Not only are you allowed to walk over it, you will struggle to complete this completely safe and easy walk out of irrational fear. The only reason this isn’t a popular attraction is it’s free. Come to the birthplace of the first Greens party in the world, because you can appreciate sheer engineering next to sheer nature, and one of the artificial lakes is a lot more attractive than the other (there is a restaurant at the nice one). Any good photographer will find this a challenge to capture. Go if the weather is cloudy and you can imagine the cliffs are perfectly suited for your next evil castle HQ.