"Still, I wonder... was this civilization built after the dungeon formed, or did the civilization exist first and then get swallowed by the dungeon?"
The third possibility could be that the dungeon was simply designed to look like a collapsed civilization, and no humans ever actually lived here. It would be a huge headache for historians, but it's not entirely impossible. After all, the Shibuya Dungeon had a whole sea inside it, so it's not that far-fetched for the Nagoya Dungeon to have buildings that look like they belong to some lost civilization... No, actually, that is pretty strange when I think about it.
: Can you see the edge?
: Nope.
: This floor is insanely huge. Are you seriously going to explore all of it by yourself?
: Come on, if Kisaragi-kun managed to explore the deep sea, this should be nothing for him.
