Months ago I read "The Lost Continent of Mu" which One Piece is likely based on, here's what I found.
First of all, yes this original post is what made me write this. I had thought about collecting everything I learned and thought was interesting for a while. This post made me get off my ass and actually compile everything.
https://www.reddit.com/r/OnePiece/comments/1wcg2h0/uhhhh_what_in_tarnation/
What's notable?
First of all, I think what's most likely is that The Ancient Kingdom is pretty much three things at once:
Atlantis, The Garden of Eden, and Heaven.
Notably, I think that the Ancient kingdom is called Eden or Heaven. The reason for this is the WG is trying to hide the name. If the ancient kingdom were called Heaven and they overthrew it, it would call their rule into question.
Notably in The Lost Continent of Mu, Churchward directly compares legends of a lost island/civilization and concludes they are all the same thing. That the Garden of Eden and Atlantis are literally the same place.
This ties in nicely with a theory I actually had a long time ago, though I do think the name is most likely Eden now (even if the rest of the theory is the same). I do think it will have a very similar name, there are other references to "The Empire of the Sun" in this book which may also be the name of the Ancient Kingdom. Overall, I do think the name of it comes down to maybe five or six possible candidates.
https://www.reddit.com/r/OnePiece/comments/1d9y494/manga_spoilers_the_name_of/
The Will of D, Reincarnation, and Dreams
There are a lot of references to the eternal soul in the book, and eternal souls are far from an original concept, but this excerpt from a secondary source lays a pretty solid groundwork for why Luffy and Roger have the same dream, and how potentially both a fruit and a person with a Will "choose" each other like how the Nika fruit has a mind of its own, and Blackbeard says the fruit chose him to a degree.
Symbols
There are a lot of ideas/symbols around the kingdom of the sun and a king who has succumbed to darkness. While I don't think Oda took these ideas one-for-one, I do think he was heavily inspired by them. Notably I think Imu is a false or fallen king, and Nika is sort of the "rightful" one.
Note that this is an actual image from an actual place, but it's condensed here. Oda is a pretty well-read person, so I'd wager he used a lot of these ideas as jumping off points and read lots of other histories, not necessarily cribbing everything from what happens to be in this book.
The Ancient Kingdom Itself
I'll cut off at this point, but this seems like a good description for the Ancient Kingdom/Eden/Whatever. It uh, gets kind of racist after this point in the description of superior races and shit. The dude who wrote this is a complete nutjob.
The Great Flood
The same basic themes are here. Note that a lot of these ideas are common folklore/religious ideas, so this guy didn't magically invent the idea of mountains becoming islands after a massive flood, but given the rest of the ideas that give some kind of inspiration, wouldn't be shocked if this is where Oda got the idea from.
The Cause of Destruction
Effectively, there are underground chambers full of gas/magma that exploded and collapsed in upon themselves, burying this kingdom beneath it.
Once again, calling upon an old theory here:
https://www.reddit.com/r/OnePiece/comments/15h7f0r/1089_a_big_theory/
When Big Mom/Kaido died at the end of Wano, this was actually showing off how the world entered this cataclysm: These volcanic/gas pockets were hit, causing enormous volcanic activity in response, raising the water level and creating new islands.
In this book, there are belts/areas of these chambers. This is probably how the red line formed. It was a line of underground volcanic spots that exploded and created a circular mountain range.
Other Things
I'm basing some of these off memory but:
- There was one continent according to this weirdo, but connected by multiple land bridges (feels like the goal of Tequila Wolf is to bring that back maybe)
The cause of the weird compass stuff in One Piece is a "magnetic cataclysm" which raised mountains everywhere, with mountains throwing all the readings off. The magnetic shift theory (I don't have a link to it, but it's one of the biggest theories in One Peice where the poles shift) that's pretty huge may have some strong basis here.
This is potentially where the idea of Ponegylphs came from. Maybe.
Finally, the last chapter is mostly about how souls can will the very world around them, which is an EXTREMELY common idea in magic and fiction, but like, hey, Haki is in here too I guess.
Anyway there's a lot more stuff in here that's pretty cool. Thanks for reading!
Posted Sep 10, 2026, 7:17 PM UTC