Oh, there was plenty of space for Kanto (and more).they only did all this crap due to space requirements on the gbc cart. It will be 1000X better in hgss i predict.
GameFreak just got lazy.
Oh and yeah the Seafoam Islands. Articuno's big cave was turned into a tiny gym/room. Wtf?
I don't know if Cinnabar was build on a volcano, but I don't think it was. Pacifidlog was built on a Corsola colony (lololol, what if they started swimming?) but I think every other Town/City/Island is plain land.