The Susurrus is an artifact-plane looping around the cosmos in the talons of The Silver Phoenix, Gaerth.
The inside of The Susurrus has become pleasant -- the hollow core contains lost fragments of Maibe's sun, illuminating a brightly-lit forested world, copied from the Forests of Brinn. It is altogether, a pleasant place, though not as verdant as Verda, nor so brilliant and magical as Yrie.
The inside of the world has a reversed gravity (things fall "down" away from the solar core),
Currently, The Susurrus is devoid of anything but simple plants.