Lights are simple too. There are 3 spot lamps with shadow buffer and one area light as Sun. The area light gives the strongest light and the strong shadows. I love the soft shadows of the area light.
Area light rendering is slow, but with dithering, we can use only 2 samples for draft rendering. This is fast, and on the final render, we can increase the number of the samples. There is a faint red spot lamp directed to the golden door. It makes a warm "glow" on the door.

At this point I have the the overall color and feeling of the picture. I had to elaborate the environments of the gate in order to fix the composition.

For the rocks and plants on the rocks (maybe grass) I used displacement mapping. The geometry is very simple, as you can see in the picture. In Blender, the displacement works by modifying the mesh's vertices, so if we need complex result, we need many vertices. So I used the subdiv again. In Blender we can set the viewport subdiv and the render subdiv.
I can set very high subdiv on render, the viewport will not slow down. I use same texture for color and displacement. But on the grass, the displacement texture has higher contrast and it has alpha channel. For alpha channel I used the color channel with high contrast.

The base geometry of the rock/grass is the same.