Ian's Cross is an official skirmish map from Supreme Commander. This map also features several destroyed experimental units, (including a crashed CZAR right in the centre, if you look closely you can see it's crater.) These should be harvested as soon as possible to bolster your war effort.
As the name states, this map is designed in a cross, leading many fights to take place in the centre. There are also pathways to the adjacent mountain that contain Mass deposits, and can serve as a good way to bombard your opponent with TMLs and Artillery.