User blog comment:Kaido King of the Beasts/The Fourth Road Poneglyph/@comment-24850639-20160321191958

I like Mariejois and the Moon. I don't think it's Mariejois, because I think Doffy's comments about the Ope Ope No Mi (personality switching) and the "tributes" due to them at Mariejois that he used to blackmail them over suggest something a lot more sinister there. Piggybacking on your assertion that it isn't "shake the world" worthy, I think it's something that the average citizen from anywhere around the world would be mortified at the WG for possessing. I'm assuming of course, that "shake the world" means it would piss of ANYONE, and not just a certain sub-group of people. It does still make a ton of sense to me though for Luffy to eventually have to go to Mariejois for SOMETHING though, even if its just to fuck up a Reverie or give the Gorosei a tropical punch.

As for the Moon, I'm a much bigger fan of this theory, though as you pointed out, it has just as little to back it up as Mariejois. People have tossed around the idea of One Piece going to space for a while now, and I have to say I'm on board, even if just to find out what Enel's been up to. The Apollo missions took 3 days to get the moon (granted, they used equipment capable of reaching the necessary escape velocity) and with a shipwright like Franky I don't think its fair to say its impossible for the Straw Hats to do so. The Coup De Burst alone seems ages ahead of any other ship technology we've seen to date, so again, I wouldnt put it past Franky. Dont have an answer though for who brought it there in the first place. Maxim showed that space travel isn't impossible for a ship, and clearly the Birkans and Skypeians have moon origins, but as far as who would have done something like that by then, who knows.