Description of Heaven
Heaven is a Beautiful Castle or Palace or Temple (depending how you look at it). Most of the rooms were workshops or quarters of the Creators, now stripped bare. The heart of the Castle is the great Crucible where the fire of creation burns. New Gods can step into the crucible to burn a Domain to create fundamental change.
Around the Castle is The Garden (about the size of Belgium). Around the Garden is the Great Wall, made of a mix of Adamantium and Ur-metal. There is no way through it, and nothing beyond it; no space, no time, no vacuum; nothing. The sky fills the top of the wall and the ground fills the bottom of the inside of the wall.
The Heaven's Gate is at the southernmost point of the Great Wall and leads to anywhere on Earth.
Each New God has a "room" which is their own semi-infinite plane, which slowly responds to their wishes and can be decorated as they wish. People can only enter with the owner's permission, and can be harmlessly ejected at their whim.