The God War was a supposed war that took place all across the explored lands. It isn't known if there were actual real gods involved in the fighting of the war, or if that is just legend. But what IS known is that thousands of ancient relics are left over from the conflict. Powerful magical items imbued with magics that no longer exist in the world. These relics are often sought by those wishing for power.
In Relic it is said the land has 'scars' from this battle. There are dead places where nothing can grow and no animals live. There are giant craters in the ground from massive explosions and unnatural canyons that were violently cut into the solid earth.
The Chasm is one such place where nothing can live. It is ruined form the ancient God War.