Den of Light
This den is different from the other dens in that there are green and yellow switches for certain big rooms around the map. Usually a green or yellow switch corresponds to the nearest big room. The final room also requires both a green and yellow switch to be pressed. For non-boss rooms, they may or may lead to paths that contain a chest (usually they don't).
Requirements
This den is only unlocked after Guarda Fortress Abyss Good Ending has been obtained.
The den drops Mid, High, and Fine grade ore randomly.
Maps
You can find which map variant it is by running across the top of the map to the top left.