I like the diagonal line of the wall, but the picture itself lacks strength. I think more contrast would accentuate the line of the wall and reduce the mistiness in the valley, but the sky might need burning in slightly to stop it becoming too light. I also think it would work well in black and white which would bring out the ruggedness of the landscape. I don't mean to sound too negative, the composition is good, the picture just needs a little help.