Well Hello Sir Pixolator, you certainly are able to demonstrate the power of ZBrush 
Iām struggling for adjectives, itās photo quality - I know how those rocks would feel, I know what it would sound like if I was there.
Would I put creatures in it? I would at least try it. A group interacting in the pool beyond the arch perhaps, maybe even a portion of one in the foreground to help illustrate the distance scale - although a foreground creature would obscure some of the rocks which I would hate to lose. (I laugh at myself thinking I just said āyeah, just toss some creatures in thereā - silly me
)
The water is superb - the reflections - did you paint these? I think what makes the water so perfect is the reflection - youāve added the blue of the sky, I wouldnāt have thought of this and the turbulence is perfect!
Would I change anything - others have spoken of the depth. My only comment is the arch at the top left center blends too much with the rocks beyond - if the interior of the arch was placed completely in shadow the blending would be eliminated. I may prefer this over a ādistance hazeā which by nature would obscure detail in the far rocks.
This said - if you changed nothing - this is most excellent

jd