There is a large spanning 'Stay Back' warning at the South East portion of the map:
V can cross it and there are side quests behind it but this is the warning on approach. Entire thing seems pointless?
Seems like something that should presented if at the edge of the map.
Update: Not an issue. Seems it wraps around into border control so it definitely covers a section but doesn't span endlessly. So, I guess there is a purpose. Just not a clear one when wandering (and not one I fully follow).