Labyrinth

"A labyrinth, as in a dungeon?" Leo asked after learning about the true identity of this mysterious cave.

"Yes. Although we don't know how or why they are created, they appear randomly in the Wilderness, and they are usually filled with monsters inside. However, if we explore the labyrinth, there's a good chance that we could find an artifact, especially if it hasn't been explored yet." Miss Camille explained.

"I see… You said that you'd acquired one of your S-Rank artifacts from inside a labyrinth, right?"

"That's right. I acquired the Elder's Ring of Regeneration inside an S-Rank labyrinth," she nodded.

"Oh? Labyrinths also have a ranking system?"

"They're mostly ranked by the monsters inside. If there are mostly E-Rank monsters inside, it will be considered an E-Rank labyrinth. There are some exceptions though. For example, if a dungeon has too many dangerous traps, its rank could be raised."