Sunney's Crater

Once a valley where the first recorded Humane were recorded to live.
Parts of the myth of Light's Sunney Valley were to be proven more or less correct. The popular theory was the Humane eventually find out that they evolved from not the Origin World's human population, but the monsters that destroyed the land, and it divided the people.
Once the story that the Humane evolved from the monsters came to light, they then called the monsters the Ancestral Species. This upset many people, and they grew listless and angrily prideful.
Some of the people wanted to bore into the cave, tame the monsters, and live in unison. The valley was dug away at sides to make more room for the residents, eventually attempting to dig underground into the walls. Others wanted to dig towards the light, build higher and higher to live above the threat of the ancestors.
It happened all at once, the caves were dug out and hit a monster's den, flooding the valley, and Humane crowded to the towers that were being built and escaped to the surface.
Once they get settled they try to recover some of the resources they lost, until one last expedition causes a rockslide and leave most of the valley collapsed, leaving a small ring left, referred to as Sunney Crater.
When the Final War was being planned, they were planning on sealing up the open caverns that could attract more ancestors and take back the resourceful land. Ever since the loss of the war however, the valley has been left untouched ever since.

"You might hear the younger troops going near Sunney's Crater. I'd advise you to alert your captain and avoid that group, it's no place for inexperienced kids to hang about."

-annoyed soldier

"It was cursed, this all is cursed. Why do we try to live in such a terrible world? We started in the caves with the worst of monsters and we live in raised cities above them, but they will never leave us alone, we'll never be rid of those ancestors...!"

-distraught commonform