Duchess Estate doesn't have a message saying it's a landmark, but still it is. Oh boy, those early access games and their bugs.

There are few places missing like Duchess Estate, Wikkan Island or Cadaver Keep to name few.

If you want I can whip open photoshop and combine the map images into one, in my game I've got nearly every region fully mapped out. Only ones I'm missing I think might require the airship.