I guess that the criterion for inclusion is "does anyone have a vested interest in including their own city and is persistent enough to fight their way through

I guess that the criterion for inclusion is "does anyone have a vested interest in including their own city and is persistent enough to fight their way through edit wars." That is, it's a fun list, but shouldn't be considered authoritative of anything. E.g., Seoul shouldn't be there. The ancient capital of Wiryeseong was a separate city that was abandoned in the middle ages (in fact we aren't even sure exactly where it was), and the most likely location is on the other side of the river from Seoul's old city area: the (suspected) Wiryeseong area wasn't part of Seoul until 1963.