Since the Main Rebel Camp can usually be found deep in the Morass Jungle, the Watch Tower is often made out of a taller tree. The special thing about the Watch Tower is that it has a telescope mounted on it that has a sophisticated rune inscribed into it's glass, when looking through the telescope the person using it can see a Soul's insignia or the remnants of one. Which means they can see approaching Tethereds or Severeds through the trees.