Hi (and hi everyone, this is my first post!),
Good job there with the render!
I'm kinda new to Indigo and 3d graph, but from what I know about composition I can tell you that your sun angle is way too perfect. I know when you do a shot you can generally wait for a point of view like that, but still... Also the columns - besides the ivy they are all the same(same texture, size etc.). I don't know what is the soft your using for modelling but with Sketchup you can adjust every texture individually for almost every object. Try to randomize it a bit. The little differences make renders photorealistic I guess. Even if you move one column like 3-5 inches and rotate it vertically by an angle of 0,5 / 1(as I remember columns in any of historical temples werent absolutely straight) you will get more realistic touch. If u go for a too perfect shot everyone can tell you something is wrong there. If you cant get a couple of models that differ one from another in a way that would definetely say it's something individual you can always rescale+rotate+rescale/rotate texture. It sure does the trick for most plants/trees and some objects that come in an array.
The two other things that I can tell is that the shadow of that lady is way too green(try comparing it to shadows cast by columns) and the ivy in the right side of the picture looks like it's flying in the air.
Try reworking that sword in the middle of the composition
These are just minor things IMO. I'm replying only because I'm trying to do something pretty similar to your work. I hope you'll keep on posting your renders too
I hope my english is understandable!