@Andromeda I personally believe that while Square intended each game to be independent of each other, they made enough connections to keep bored, observant fans busy between releases. I'm pretty much doing this for the fun of it, since I've already done so with Dragon Quest and Super Mario. As for the tower in III, Xande used it as a hideout after flooding the world. I never talked to Doga and Unei much when they were in my party, so I'm not sure if Xande or someone else built the tower, if that was brought up at all.