You know one thing I realized from the spoilers is that Roger didn't leave treasure on Raftel. I always thought that One Piece was partially Roger's accumulated wealth, and he left it at the last island for people to find along with the history aspect. The spoilers now make it seem that the treasure was rumored to be there already, and it's not Rogers. So who left it there? Is it part of an ancient civilization; possibly a city of gold type treasure?