it depends on the angle you have towards the castle and -of course- if the back wall has the same height as the front wall. If it has the same height and its at the same level of elevation as the point of view, you wont see it.
On a side note:
Actually I am using a “fake perspective” for all the buildings. All interactive buildings (and the stronghold) are painted as if point of view and object are on the same level of elevation, wich wouldnt be possible in reality. I leave out the foreshortening.
Reason for this is that the buildings will appear on random spots within the village so I have to paint them in a way that they always look okay, no matter where they are placed.
It’s a bit difficult to explain, but I hope you get what I mean :)
This is what the real perspective might roughly look like: