The Cosmos, man . . . what a trip

 Starting outward and going in . . . 

The Far Realm, a place stretched beyond comprehension beyond the boundaries of reality. 

The Edge of the Astral Sea, where the Outer Planes dwell, each home to realms of gods/demon lords or a god/demon lord.

The Astral Sea, which stretches it's self to the edges of it's massive sphere and in which all else resides. 

Crystal Spheres, in which Wild Space begins for each setting. Home to planets, sun's and the core material realm of a specific setting. 

Material realm, of the setting. In our case it is home to the planet Illmakaria.

Planet Illmakaria, home to the continent of Karnantha. 

Karnantha, Home to countries like Ashura.

Ashura Kingdom, home to the great walled city of the same name Ashura City. 

The Fey Realm, a copy of Karnantha remade in the fey's image.

The Shadow Realm, a copy of Karnantha reamade in the shadow fey's image. 

The Ethereal Plane, a reflection of Karnantha as seen through shadow and mists.  

The Elemental Planes (Inner Planes), a massive ring of planes made of the four elements that connect at the borders giving way to four distinct transitional planes that all converge at a central plane of absolute Elemental Chaos.

Elemental Chaos, the most central inner plane of unbalance. 

 

As for places like Sigal, the city of doors. I would have to interpret this as being in it's own Crystal Sphere without other planets, but with a sun. The only landmass more so than a planet would be Sigal and it would have the corresponding gates to the Outer Planes from the Outlands that surround the tower.