Concerns
The steep hill... That spot on Planet Greenland that has recently become extremely famous as the Devil's Head, after all, it is from where the invaders emerge.
But most of the locals did not know that that hill was randomly chosen to build the space portal on, and thus Robin and the rest were forced to make it a permanent foothold for the Empire on Planet Greenland. The steep hill was not the best choice for building the space portal, and certainly not the best choice for building a city!