I don't think there's any way to get down from the guard towers in the Hydlaa Plaza. I entered the door at the base of one and was moved to the top of the tower, but there doesn't seem to be any door that leads back down. The tower is just an ordinary watch tower, like the rook of a chess set. There are no hidden areas or anything, just a large platform with segments of wall around the edges. Without a door to go back down, the only way off would be to jump, which will likely kill the falling character. If I'm missing something obvious or if this is supposed to be some kind of puzzle just tell me, but it seems that this is a game glitch with forces players to die. And if this is supposed to be a puzzle, it's a very strange one; when someone climbs a tower, it shouldn't be a mystery where the door to the stairs was.