Don't you just hate it when you are setting up a nice shot of a river, and just as you pull the trigger a tree jumps in front of the lens! Photobombed by a tree [Brian is a bad influence!]
I like this a lot, Martin and Rob is right about the rhythm created by the composition I think. As for photobombing, I'm sometimes so slow at composing a shot entire valleys appear before I know it! You are lucky you didn't fall into the ravine!