Isaac was rather casual about choosing a location for the Underground Palace City. As long as there were three to five Underground Palaces nearby, it would be enough. He needed to create the impression of a normal conflict for the Demon Gods behind those Underground Palaces.
As for the terrain...
The name of this world, Wilderness Dungeon, was quite telling. This world was either Wilderness or Underground Palaces. The vast majority of the land consisted of boundless great plains, and the few strategic locations had long since been occupied.
Besides, Isaac had no intention of being the public face of this Underground Palace City. He wouldn't even provide it with technological or material support like that one Grand Arcanist had.
This was for the Trial mission, and it was also a part of Isaac's attempt to defy the Great Wizard!
Soon, Isaac found a suitable location—a small hill that was easy to attack and difficult to defend.
