Well, I'd usually just call it The City, since the one metropolis contained the whole of the imPort population. We actually encountered enough other imPort worlds while there that this might qualify as Earth-Zeta, anyway, if we follow that designation.

[ Though she's only vaguely spoken about one of them since coming to this world, and that was over two years ago. Though New Vesuvius has always weighed somewhat in her mind, as the only one of them that had a distinct Porter she interacted with. ]