Plateau

The place they finalized as the site was a ginormous plateau that didn't need much terraforming to construct the entire shelter on top of it.

A mountain range was adjacent to the left of the plateau where numerous dungeon portals had materialized over the passage of a dozen years. Many of them were permanent dungeons that released countless dungeon beasts every now and then.

Thus, the mountain range had turned into a place that was fully claimed by more or less powerful monsters. Nial wanted to make use of that since the Originals willing to populate the new shelter would have to get their hands on beasts to hunt them. Dungeons and beasts were present in abundance in the mountain range and it wouldn't be a problem to become rich by adventuring through the mountain range for a single hunt.