I think there are two things that may have hurt the score. First, it seems a little washed out to me. You might try increasing the contrast, or bump up the gamma just a little. Second, the description of the challenge was "Time keeps on slippin, slippin', slippin... into the future". I don't see much here to show the "slipping" or the "future". For the record, I gave it a 7. I like the composition.
This is just a thought, but try standing at the base of the clock tower portion and shoot straight up. My wife did that at St Patricks Cathedral in Dublin and it was really cool looking.