Favourite One Piece world building?

[Pocket-Gog~]

Oda is pretty great at world building in One Piece.

Lotsa events criss cross and intercept, characters are revealed to be inspired by other characters. Sometimes a character is responsible for something in the past. What is your favourite example of this?

 

[Captain Cadaver]

I'd argue against OP's world building being good due to poor constructed ecosystems and weird choices in governmental extent and the Oharans, not to mention its power system becoming immersion-breaking at times (especially after the timeskip) but that's a topic left for another day.

I'd probably say Alabasta. It's quite simplistic compared to later elements, but a lot more consistent in its fleshed out political landscape and history.

 

[SSJ2]

Definitely Ace dying.