you can just make out the wall if you look really close.
looks very good btw
what writing are you going to put on the grave?
also i dont know if you plan on having the moon glowing but a moon doesnt really glow like that. might give it a more realistic look if you take away the glow.
http://www.grand-illusions.com/images/moonphoto.jpg
http://astrogeology.usgs.gov/assets/wallpaper/moon.jpg