Inferno Hollow

Inferno Hollow is a location in Final Fantasy Brave Exvius. A volcanic lair located in the Grandshelt Isles's northermost island (and part of the Kingdom of Grandshelt's territory), it is home to the esper Ifrit.

It is an optional dungeon that can be unlocked by going to Port City Lodin, and talking to two NPCs in order so as to unlock the optional Ordol Port. Once the player reaches the town, they must talk to the boy under the shop to unlock this dungeon.

Story
Long ago, Ifrit was sealed away in the the cave, where it would attack intruders with the ferocity of a savage beast. Eventually, and while on their way to Dirnado to protect the Wind Crystal, two knights of Grandshelt, Rain and Lasswell, journey to Ifrit's cave in hopes of receiving help from the esper so they can become stronger. Upon completing his trial, they are bestowed with his power.

Trial of the Fire Beast
It unlocks when Ifrit reaches level 30.