Arcadia
Tales say that at one time the people of Arcadia traveled between the stars, plying the great emptiness between them like sailing on the sea. Some say that the Silver Towers of Avalon were one such ship, though aside from some fanciful decoration and unusual architecture no one has ever proven anything. The Starborn claim it was they who sailed here, bringing the Terrans, Grel, and Uplifted with them, while the Tivs say they have always been here. Truth is, no one knows because of the Collapse.
The Collapse came upon us all by surprise. We had great cities, larger even than Avalon, machines and factory, farms that stretched for miles being tended by great machines that would crawl across and tend them, the bounty of the land providing for everyone, the factory mines of Mekann creating great wonders, the metal bones can still be seen in the wastelands. Yes, it's said that Arcadia was a paradise, but then, the Collapse. Monsters never before seen came out from the woods, emerged into tunnels, or rose from the sands, seemingly every city at once was under assault. It didn't take long until almost all of us were wiped from planet, our great advancements, our knowledge, or wonders, all of it ruined and gone. Then just as we were on the bring of being exterminated completely the monsters all left, back to where-ever it is they go.
We learned, small villages, no more factories, no more great rumbling machines. The Tiv came out to meet us and teach us, helping us to live without provoking the monsters. It mostly works, villages or homesteads are still sometimes wiped out with little or no warning. Mostly, we're surviving and gaining back some of what we've lost.