The Elan Valley is one of the must-see to any visitors heading to South Wales. As I've not visited the Three Gorges in China (I was told that it's more spectacular), the Elan Valley suitably impressed me. As per all dams, the construction submerged large swarths of land. There was this church that was submerged (we can't see it of course) but a replica was built to replace it above the water line. That picture was not uploaded. That building that is in the picture on the left is actually a controlling station. Notice the waterline on its side during hightide.