Lake Sinoa Cave
From Aselia, the Tales wiki
The Lake Sinoa Cave is a small underground labyrinth which is revealed when the water from Lake Sinoa dries up. Lake Sinoa is the lake upon which the town of Luin was built. It is connected to the Tower of Mana.
This is where Lumen's core is found. As the Summon Spirits of Light made their pact at the Tower of Mana, it is only fitting that the resting place of the Centurion of Light is here.
After Emil wakes up Lumen's core and the others are preparing to chase after Richter into the Ginnugagap, Lake Sinoa has completely been flooded by water again. So this place is unaccessible after halfway through chapter 8.
