Black and white was my first insinct as well but it looks great as it is. The only suggestion I could add would be to go back on a stormy day and do an HDR of it. I think that would look quite good and it would certainly add to the mood of the photo. I also had a go at processing the image, but I left it as full colour and gave it a soft, diffused look which I think looks effective on this photo, but I'm no expert so it isn't perfect. I hope you don't mind!
Here it is:
I can remove it if you'd like me to. Please don't be offended!