Prompt:

The high ancient tower built by the elves. Painted walls. National Geographic poster photo. Colorful. Futuristic.
Beautiful intrinsic details. Magical, photorealistic. Inspired by Michael Whelan.
Mythical, tropical, amazing. Broken light, sunrise. 
Award winning, trending on art station.
 

Negative prompt:

Text, watermark. Unsharp. Less than awesome. Towers in the clouds.
Drawing, cartoon, painting.

Model:

Real Mix XL

Notes:

The word Futuristic in the prompt clearly did not have much impact. I am curious if "Less than awesome" in the negative prompt did. Sometimes it has success to add that sort of phrases. Which clearly had impact was "Towers in the cloud" . I got a lot of images where there were also towers in the background, more or less floating in the sky. Adding this helped.

To get it as photo realistic as possible, I added Drawing, Cartoon, Painting to the negative prompt. Fantasy is of course often painted, not photographed.