the fountain where there is the "residences" gate and a crystalisk. it might look as industrial but it's not the industrial sector is at the opposite end of the map which can be proved

and also GUYS PLEASE where does the office sector lvl 2 rail lead to (it's next to the elevetor to lvl 3, the doors are closed but it tells that the're opened from another side)
I built a path around from the data farm rail and it led to hydroplant but I could't find the rail which I guess leads to nowhere