Looking good AS, I'd add a load of pipe work or support brackets to brake up the ground entry, also dirt would tend to build up so it may be worth raising the terrain or adding a small terrain so that the base is stacked with dirt. The only other thing that looks a little odd is that the door numbers are different ways up, there again, maybe be that's only me!

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Toolset: Blender, GIMP, Indigo Render, LuxRender, TopMod, Knotplot, Ivy Gen, Plant Studio.