A cave said to contain Captain Selene's treasure, Treasure Cave (秘宝の洞窟 Hihou no doukutsu) is a cave to the east of Ilias Port.
Luka travels there after receiving information from Amira that the cave might contain the Poseidon Bell, a legendary item said to allow any ship to steer through the roughest of storms.
En-route there, Luka finds that the cave actually is far away from Ilias Port, such that he has to spend the night in a camp. He comments that "if I knew it would take this long, I would have spent the night in Iliasport.I thought it would only take a few hours,but we're barely halfway there."
Upon arriving in the cave, Alice shows her fear of ghosts for the first time to much comedic effect.