The transporter that can take us back to the "control center" station is in the ruins of another city, south of the mountains. Wali believes that it was destroyed by the obelisks, just like the city in the southeast.
I didn't press her for details, not that I'd have gotten any. Wali's more tight lipped about those ruins than anything. I had to practically beg her to take me to the southeastern city, and while we were there, she spent most of her time just gazing out into the distance.
No sense in bringing her mood down with that rubbish now. After all that she's done for me, I'd like give her a nice, proper farewell.