Portal in the mines? *spoilers*(maybe)

[Xoyv]

so, curiosity bequeath me, but primal fear stops me, where does the portal in the antejuice pool in the mine maze lead to?

[Monokuma]

It's not a portal world, so you don't have to fear anything like that. You're safe to go through it.

[ULTRA]

Believe it or not, you're already on the painful end of the portal

[Seneric]

I dont even understand the point of the whole portal.
Seems to lead to nowhere useful.

[mr steal ur spell]

That area of the mine seems to have been designed with alternative paths in mind (IIRC the portal takes you up to a shortcut towards a large building) but because the spawns are few and far in between it feels empty and maybe a bit pointless.