Thank you for all the nice comments
@grif:
The canyon walls are flat, it just didn't show in the smaller test render before the big one

I may add some noise.
The bridge isn't connecting to anything in particular, i just wanted to show a "crossing".
the water is supposed to look a bit fluorescent, just for a fantasy feel. The effect was multiplied when i applied the softglow, i guess that's what's making it look weird.
Thanks for the constructive comments
I may work on it and post a new render.
Just FYI, the post is above, so stop looking down here and do something useful.
king noob. Nice.