To emphasize scene and divided between an architecture forms I created some organic shapes. It'll be enriched with some other organic models of flowers, mushrooms, blade of grass etc...

And quick messy view of whole scene - bump map which is must for terrain hasn't been applied yet.

 I have made some tests with terrain, however the amount of polygons scare me off so I am going to apply only displacement or bump map - most of it will be covered by grass anyway.