The bottom-right cell is the most maritime cell. There are probably a lot of ports there. I also suspect that the capital is located there. It should be convenient in this regard, to get to/from it.
The bottom-left cell. Close to Ples's homeland. Perhaps it would be logical for him to settle there.
The top cell. Close to the merchants, so you can organize more convenient trade. Well... In the future.
I'm for the bottom-right cell. Especially if the capital is indeed there.