This image was made in Terragen. The castle and moat had to be shaped out of the landscape since adding other objects wasn't an option. I thought it turned out pretty believable considering the limitations of the software.

I used Terragen for this mountain-scape. No plants or other objects, but I was able to use the terrain coloring to suggest vegetation and rocks. It makes me think of Yosemite National Park. All three mountains bear some resemblance to the Half Dome there.