So what's the forge world like? Is it a city world like coursant? Towering hives complete with plenty of open spaces?
YES! The mechanicus! Thank you! Stupid brain.
But not like Courscant with the total covering of massive buildings. Still industrilized, but not with nothing but 500 story buildings. More like a city battle in the post-apoc Detroit. Lots of blasted industrial complexes that might as well be mechanical Forrest, if that makes any sense.