The late angled light of day is striking the towers, flying buttresses, and myriad of details just right, producing shadows that aren't so deep they hide detail. The light and treatment is making the whole structure glow. The colors are amazing and you've used just the right amount of HDR. I think that HDR has been a little overused for some images here on the Caedes site but not in the case of architecture, which is enhanced by the technique. You've done a great job with this one.
If you've ever wanted to make a difference but found it hard to believe that one person could... check out the Kiva Team Caedes discussion thread and discover that anything is possible.