Back there with a new building…
It took time as i had hard time with the creation of a displacement map in blender.
see here: Baking The Perfect Displacement Map (Blender + Cycles) - #4 by pitibonom
Anyway,i had the very helpfull answers of @Secrop who made an HYPER HANDY plugin that should be bundled with blender 2.79.x as it appears to be the only way in these versions, to bake displacement maps with cycles !
Again, a big thank to @Secrop for his work, help and patience ( a lot is needed with me 
)
So here’s the next architecture piece of the walls behind the castle:
It’s a little watchtower settled on the western wall of the main city castle.
Hope you like it 
Happy blending !