The Singing Grotto

Deep below the mountains of Syl'Vorn, in the heart of the Courtless territory, there are a series of cave systems that were thought to have nothing but empty space for a long while. A small stream runs - or slowly crawls - through these caves until it's reduced to drops of trickling water, somehow finding their way deeper inside the narrow and twisting tunnels, but even that is just... water. There are some minerals sprouting from the walls, but even those aren't valuable enough to justify all the trouble that setting up there would entail.
Even so, there are those to whom the mysterious is merely another challenge, another thing to explore. Throughout the years, decades, centuries, some dared to explore the tunnels below Syl'Vorn, to go as far as possible, and sometimes even beyond that. The ones who managed to return came back with the right to boast that they'd done so, an experience marked off their journal of adventures. But the ones who actually managed to reach the end of the caves... none of them really wanted to come back.
They did, eventually, and brought with them tales of a magnificent grotto at the end of the labyrinth. A place of pure bliss, where the walls sang a never-ending melody, beautifully haunting. Where will-o-wisps floated freely and bathed everything in tones of blue. Where fish swam in ponds, berries grew on moss, even though no sunlight ever reached the place. Where everything bathed them in a sense of complete awe.
Tales of this rather quaint and eerie locale spread, but many believed people had been driven mad by their journey, that there could be no such place below Syl'Vorn. Why would there be? It became a story, a rumor, like so many others in the Feywild.
Some believed, though. Some had already seen it, and so they convinced their families, their friends, that this place was real, that it was there, if only people dared travel to the very end. And a small part of them did. They came back, they showed others the way, and eventually, finally, settled on what they would call The Singing Grotto.

The Settlement

Not a lot of people live there at the moment, but that's just as they would have it. The cave wouldn't house more than a hundred people anyway, and this way they can stay silent enough to hear the walls sing. Or perhaps the will-o-wisps are the source of that beautiful melody. Either way, there doesn't seem to be a concrete source, but it fills the place without pausing, without repeating itself, always changing, shifting, becoming something new.
Since it's such a arduous journey to get there, and to get out, people don't really bother doing it, so they have to depend on the resources available at the Grotto. Even though the stream is but a handful of water once it reaches this place, there are still several ponds throughout the Singing Grotto, deep and wide, full of fish which shouldn't even be there to begin with. There's no light besides the one the will-o-wisps shine, and yet there's still moss on the walls, a moss which grows very nutritious berries. Some people are able to create food through magic. That seems to be enough. Some materials were brought by the settlers to build their houses, their comforts, and there are healers who keep everything in check, although they have never been needed for anything but scrapes and bruises. Everything seems to be at a perfect balance within this cave, this utopia deep within the earth, down at the end of the path.
Those who settle in the Singing Grotto are content to live the rest of their lives there, listening to the music, watching the water reflect the light unto the cave's ceiling, to share that with the others who've made this strange place their forever home. It might seem strange to many, to live isolated from the rest of the world just because you... felt like it. But then again, cities are weird in their own ways, with all their chaos and cacophonies. This makes sense for these people - all they want is peace, and quiet, and music. Oh, the music.
And that's enough.

Green Hell by Florian Aupetit