Experimenting a bit here. I cut three pieces of foam to fit into the corner and between the structures .. then hot-glued them together. What I want to do is carve a hilly slope that connects the two into the backdrop.
The ‘method behind the madness’ is to give the impression that the buildings are built on very un-level ground. Retaining walls inserted at the appropriate locations and winding steps and roads should help. The slope itself will be rubble and dirt with perhaps a little grass. There’s not much room really but should be enough with trees against the backdrop to hopefully (and magically!) blend the scene into the backdrop. I’m thinking though .. that this will be pretty much an example where forced perspective may work since the buildings form a view block and restrict the view .. so that might work better then if it was out in the open.
Just how well that works is still to be seen. I’m thinking though .. that if that little bit of foam is left ‘loose’ .. then like the buildings, it can be taken to the workbench for detailing.