What a coincidence! I was there at Skogafoss just on Thursday and now am back home in England checking the watched artwork which I have let pile up over the last month. Anyway, this is a beautiful photo and now holds many memories for me. The rainbow is lovely, as always. Faved!
It looks like you have darkened the sky here and it has caused a halo? Otherwise this really is a fantastic shot. I am a sucker for rainbows and to have such a spectacular waterfall as well is a real bonus.