Yarasasi (ヤラサシ（大蝙蝠洞） Yarasashi (Ōkōmori-dō); Literally meaning "Great Bat Cave") is a cave located in an unknown location, as well as the secret hideout of Mezar, a Dark Mage responsible for the destruction of what is called today the Forgotten Lands.
In order to access Yarasasi, one must overcome three trials of endurance. However, these three trials are not normal, as the locations are engulfed in a magic curse that prohibits the use of magic. Because of that, the person that intends to access the hideout must have tremendous physical attributes. No magical items are allowed, as they are rendered useless with the curse, as well.
Three three accesses are the following: The Hundred-Thousand Stairs Trial, where the person must climb one hundred-thousand steps; The One-Step-to-Disaster Valley, as the name implies, is a valley that is composed of extremely fragile rock and a very small place to step; the last trial is The Itiraz Mountains, a mountainous region that needs at least two days to go through, but contains no resources and a single hideout with place to only two people, making the challenge harder to a group that intends to stick together.
- "Yarasası" is Turkish for "bat".
- "Itiraz" is Turkish for "challenge".