magic world for an rpg or a comic.
village build inside huge meca, castle are meca, sorcerer tower are... wait for it ... meca.
huge fight between two city who take the form of a humanoid.

vas plain and quarry with huge living construct titan with all inhabitant who get out to work.

in a dnd world, it would be an eberron paralel universe with warforged juggernauth. maybe city sized could take the stat of the tarasque.