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This photo shows the surface-level structure of the Underground Geyser Center located on the Youkai Mountain. It serves as the facility's entrance and closely resembles what is known as an ultra-deep mining shaft. Elsewhere, in a more easily accessible location, there's another building that acts as the center's cultural archive.

Excerpt from R's report: "Whoa, an ultra-deep mining shaft! That's what this is, right?! I wonder if it's real. If it is, I wonder how deep it goes... Hmm, I'm pretty sure the deepest humans have ever dug was something like 12km. That's nowhere near deep enough to reach Hell's ceiling."

Excerpt from M's report: "Ah! What is this place? I-I don't feel so hot. Were there, like, super resentful vengeful spirits here at some point? Or maybe they're still here... Yikes. I wanna get outta here."

Excerpt from R's report: "Hmm, smells like volcanic gas. Better get out of here so I don't breathe too much in. Apparently, some poisonous gases are colorless and odorless. Dying from a gas like that would be easy to mistake for divine punishment or the work of lingering resentment."

Excerpt from M's report: "I feel like I can almost see something. This is the complete opposite of a shrine or temple, but maybe that's why the people of old treated places like this as sacred grounds or forbidden zones, marking them off with boundaries. Wait... is it an Izanagi Object I'm sensing? I wonder if there's one hidden nearby."