Burning Island Cave

Burning Island Cave (火山島の洞窟, Volcanic island's Cave) is found at the center of a volcanic island, to the south of the Ayuthay peninsula.

Story
In ancient times, Burning Island Cave was one of the chosen hiding places for a piece of the Umbra Gear, specifically the Umbra Knuckles. It's location was marked on the Umbra Map, so that future generations would be able to find the Umbra Gear. Matthew's party would travel to the Island during their search for the Umbra Gear. The cave entrance is initially hidden, and only after Himi's Search Psynergy is used, does the entrance reveal itself.

The lower level of the cave hides a secret chamber, which can only be unlocked with the Sol Blade. Should Matthew's party travel here and unlock the chamber, they can descend deep into the cave, where they will encounter the powerful Ogre Titans. If Matthew's party defeats the Ogre Titans in battle, his party can gain the ability to summon Daedalus, which is located on a summon tablet in the cave.

First Visit
Use Grip on the horizontal stone pillar at the rear of the first room (1F) and go down to the lower floor (B1). Here, use Eoleo's Thermal to reach the left of two moveable pillars on the upper floor, and push it down below. Now the chests above containing the Umbra Knuckles and Jester's Armlet can be reached using Thermal, and the Mars Djinni Flare can be floated up to the upper floor. Pushing down the other moveable pillar allows access to a locked door of the same type found in the entrance to Otka Island.

Optional Visit
Return post-game with the Sol Blade. Use it to open the door that leads to the Daedalus summon, but first the player must defeat the five Ogre Titans.

Collectibles
Umbra Knuckles: located in a chest on the central pillar of the upper floor. Can only be reached after using Thermal from the lower floor. Jester's Armlet: located in a chest on the left-most pillar of the upper floor. Can only be reached after using Thermal from the lower floor. Flare: initially found in the lower level of the cave. Can be battled after using Thermal to lift him up to the upper level. Daedalus: found in a hidden cavern only accessible after gaining the Sol Blade. Must fight the Ogre Titans before collecting.

Trivia

 * Burning Island Cave is the only location that holds a piece of Umbra Gear that also holds a Summon Tablet (as well as a Djinn). However, it cannot be accessed without the Sol Blade.