Ori and the Will of the Wisps
Luma Pools is to the west of the Wellspring, providing water for it. It can be accessed after clearing the Wellspring. It is one of the two areas in Niwen with clean water after the Decay thanks to Strength of the Forest, the first being Kwolok's Hollow.
During their quest to find the Wisps, Ori travels to Luma Pools to find the Strength of the Forest. They soon find Kwolok and he leaves to find the Strength of the Forest. Later, Ori finds a Stink Spirit possessed Kwolok, whose eyes has turned white. Ori is forced to fight him in self-defense. Kwolok regains control of his mind, but is badly hurt from the battle. He crushes the Stink Spirit and has one last conversation with Ori. He then dies, and disappears in a flash of light. The Strength of the Forest appears as he dies, and then merges with the other Wisps.
Normally, Luma Pools is only accessible after Ori obtains Kuro's Feather. However, It should be noted that by triple jumping off of the highest point near the entrance, using Spirit Smash for extra air and wall jumping through the spikes can allow Ori to access this area immediately after clearing the wellspring. This can allow Ori to get the Swim Dash ability before going to the Silent Woods and see Kwolok even after his death.