Ok, so this is what I have in mind, going from the whole "journey" of One Piece I think it represents the human progress in general, it is a journey where everything seems to get "scarier, bigger, more advanced, more complex" as the story goes on, more characters, more information as well, it is a like a world we are yet uncovering.
It can also be seen as an allegory on geography and the Great Geographical explorations, I mean we are clearly moving from East(Alabasta) to West(New World) as represented allegorically from the real life world.
Can you see some more comparisons and allegories in the manga as well?
OP always had a strong element of geography in it, which covers both technical aspects (e.g. log pole) and the actual geography. The grand line obviously represents the equator dividing the world into two halfs. Looking back at it, you might say that after the F.I arc Oda finally completed all possible directions in which the strawhats could possibly travel (up, down, left, right ).
I think that the reason Oda picked a line that can't be entered by a particular sea has a wonderful meaning: It could mean that no matter you're from, you're able to go to the top. Maybe I'm reading too much into that, but I like to think it this way.
im not sure if this is the right forum for this....but in every pirate map...the treasure looks like a big X.
1. the strawhats needs to go back to fishman island...(i dont think they can backtrack...so they need go around one more time? or there is another pathway?)
2. need to get back to laboon once again.
3. all blue is a sea that converge into one.
4. only guy who knows how to read poneglyph and hears the voice of all things will find one piece.
***strawhats ventured on almost every type of journey - sea, land, sky and underwater...only two things left, space (which im not sure since its a pirate world) and underworld (which is likely possible since its a pirate world.)
**** now, what im thinking is:
WHAT IF (a big IF) the reverse mountain (the VERY TOP) is the entrance to raftel???....and doesnt it look like that the reverse mountain, when you look at it on eagle's eye view...looks like a PIRATE MAP'S X?????
1. maybe they would enter a world under....like hell or another underwater passage. in order to reach a secret island and another secret route to fishman isle.
2. laboon is just on the other side.
3. reverse mountain converges ALL the 4 seas.
4. robin can read poneglyph and luffy hears the voice of all things...maybe if they reach the other side and gone back to reverse mountain...its a dead end. then luffy hears a voice to turn the ship upside down to find a secret passageway in the reverse mountain. (this would be much more likeable if they recruit a ship-coater----get why? turning the ship upside down)
You'll find quite interesting that you had the same idea and sometimes even the same words than mine from almost two years ago
I do not really see any allegory in One Piece. Allegory means that the symbolism is direct, representative, and only applicable to a single concept. The grim reaper is an example of allegory: it is a direct, artistic representation of death, and holds no other symbolic meaning. While there is a great deal of symbolism in One Piece, none is allegorical. The themes, symbolism, and subtext embodied in the characters, settings, and plots can be applied in many different ways. They are not limited to a single allegorical concept such as in Everyman.
At it's most basic One Piece is an epic quest along the lines of the Argonautika. Roger's treasure is the Golden Fleece and the Strawhats are the Argonauts, sailing through a mythologized world in a quest to recover the great treasure. Like all Jump manga the basic theme is "Ambition, Friendship, and Achievement". At the beginning of the manga Luffy sets a goal, to become Pirate King. He quickly sets out to make that ambition reality. On the way he makes a variety of friends, who's help is essential to making his ambition reality. With his friends help, he will ultimately prevail, achieving his goal of becoming Pirate King. This is the long time theme of Weekly Shounen Jump, virtually every manga in magazine history has worked some variation of this theme.
The other major theme is individuality, liking people for who they are, and being comfortable with yourself. All very unusual themes in shounen manga. All pirates represent individuality, living life on your own terms. In One Piece, individuality alone is not a positive trait, as can be seen by Pirates like Blackbeard or Crocodile. It is pirates who have self confidence, accept others for who they are, and use their freedom responsibly that are generally portrayed as good guys. Conversely the World Government symbolizes conformity, blind adherence to rules, and excluding those who are different. Like pirates, Oda does not want to portray everyone with a connection to the government as evil. Many Marines are portrayed as men of honor, valor, and kindness. Garp, Aokiji, Smoker, and Sengoku have all had opportunities to be portrayed as men of good conscious. None of the characters are allegory though. They do not represent a single, symbolic quality but are fully nuanced characters meant to demonstrate the greater themes of One Piece in multiple different ways.