Speculation. Many ViDocs of Mars there's these deep, steep-walled canyons shown. The Planet Mars ViDoc the city that's featured within the surrounding area there's places that are sunken into sandy pits. These features could have been formed from volcanic activity. A piece of concept art of a large Cabal fortress in the upper right corner is what appears to be a huge explosion and pieces of matter ejected from within the plume. Considering a number of the cityscrapes show a plateau or masas in the background and the sign of Tharsis Station may indicate the Tharsis Plateau. Taking all of this the possibility that what has been shown for gameplay is within the Noctis Labyrinthus region at the foot of the Tharsis Plateau .