Hmmm... the issue with Jedda can't just be impassable terrain, I can march my armies all over that province but can't build watchtowers. I don't recall a natural disaster there but who knows it very well could have happened.

Strangely, I had the same issue in RTW -- I've been under the impression that watchtowers just can't be built there.

Has anyone else ever built a watchtower in Jedda? This would confirm that I'm just being affected by the natural disaster bug.