It was a bit of a tight fit, but I was able to enter the cave in the end.
After entering the cave, I found myself in a secret underground beach.
This cave was still connected to the lake since the rocks were just on the side of the lake, but there was also a sand path that was beside the lake that seemed to be leading underground.
It seemed that there was some kind of hidden cave that was under the water.
I didn't really understand how the cave wasn't flooded with how it led deep into the ground, but it seemed that there was something there that was keeping the water from reaching the sand path.
This wasn't a place that I was familiar with, which made me a bit doubtful that this was the right place.
I only knew that the dungeon would appear somewhere near this area because that was how it had happened in the game, but I had no idea if this cave would actually lead to the dungeon that Undine was in.
So I asked Ifrit, "Ask them what is deeper in."
