When I talk about composition, you should take my statements well salted, as I'm not pro in the area. However, I feel the horizontal framing is interfering with the vertical lines, and somehow the total impression of the image leaves me a bit tense. As a general rule, when I take a picture in which I know there will be vertical lines, I take it in portrait orientation.
Why? That is the question. Why did you take this picture? What made you decide "I need to photograph this?". That is something people should think about, imo. Because, that feeling, or that which made you take the shot, that is what you're trying to tell everyone looking at it. Sunset pics often are nice sunset pics, but the feeling of it is hard to convey that is the challenging part: making the viewer feel what you felt when you took the picture. So, having an idea of why this particular scene interested you is smart. If you're not feeling anything, you're just snapping for the sake of taking pics, which rarely leads to anything particularly interesting.
Horizontal framing often leads to a feeling of calm, beauty, relaxation and such. Landscapes, great valley views or a still morning by a lake could be examples. Vertical framing can imply pride, "standing tall", something divine or great. The same goes for vertical lines. Diagonal lines imply some sort of motion, as does curved lines. Framing has a great deal to say of how a picture feels, and the specific scene decides the framing of the picture.
I'm not saying a vertical framing would be better, but I'd like to see what it looked like as there are so many vertical elements in this picture.
edit: it's ridiculously late now, and I need my beauty sleep!