Parallel plane

Prime echoes are planes of existence which exist in parallel with the Prime Material Plane. They are defined by a shared geography, bestiary, and are more easily reached than other planes by inhabitants of the Prime. The prime echoes were created in the days of creation when the Primordials, mighty beings on par with the gods, split the Prime into three parts, finding some parts "too bright" or "too dark." The two prime echoes created were the Plane of Shadow and the Feywild, though the Plane of Shadow has since been replaced by the Shadowfell.