Faultline is the same way. If you compare Echo of Faultline to the current Faultline, there isn't much difference to the layout. They removed the buildings at the bottom of the canyon and topped it off with water but the canyon walls are all still there. I found this out when I found a hole in the map, through one of the undamaged buildings no less. Below the map where you cannot see, there are canyon walls extending down almost as far as the war walls extend up. That why the zone was always so laggy.
Pretty sure all the lobbies are below the zone's ground level. I know hospitals are, and there are multiple floors to the rez ER rooms, found this out during the same exploration.