Castle.

[bla bla 2]

Open a comments. 

[Upon Infinity]

Way, way too plain.  There is no texture or vegetation on the ground, and the castle seems too simple.  Go to TurboSquid if you want to get some decent architecture, much of it for free. 

[Mr_Lamppost]

I can't argue with the preceding comments about the overall image but I am impressed that you built the castle purely with displacement.

You have quite a few render errors which I assume are related to the problems described in this support topic: http://www.planetside.co.uk/forums/index.php/topic,16496.0.html

[Markal]

I really do love castles....I hope you can improve on this and then share it with me

[Dune]

I think this is 'proof of concept'. Bastien is a very experimental guy and doesn't strive for photo realism, as far as I understand. Like his china wall, it's all displacement, as Mr. Lamppost remarked. I like the idea.

[bla bla 2]

Thank you verymuch. 

[bla bla 2]

not comments ? 

[Dune]

It's a nice find, Bastien, but I think more users go for photo-reality, and thus refrain from commenting. But it's arty, though not really my 'thing' either.
What you should try is set compute terrain to smooth terrain and a very small patch size (1 or less), then add fake rocks to the castle walls, by the same mask, maybe set a little wider with a color adjust. If you worked this out the way I guessed.

[Dune]

I did a quick setup, self-explanatory. Maybe it's of use to you.

[Mr_Lamppost]

The basic idea of building purely with displacement is interesting and if you can get it to work in your scene Dune's set up looks promising.

[Upon Infinity]

It's better.  Now that I know the architecture is displaced, it makes it more interesting.  I think I have a preference for modeled geometry, however.