Cave of Mountain is a location in Final Fantasy Legend II. There are two entrance into this cave, and the southern entrance leads to a dead end, but contains a single treasure chest.
The party comes here searching for Lynn who came looking for a potion. While venturing in the cave, they meet up with Lynn. She tells the party that she fell down the slope and got stuck down here. She can't go on head because Dunatis is blocking the exit so there's no way for her to return home. The main character tells her they'll go together, and she thanks them.