Written by the scholar Jack Spades.
"Dragons are a universal constant. Every plane, nearly every crystal sphere and quite a bit of demiplanes have dragons in them. This is just a recursion of the multiverse itself. Just as the threefold nature of the planes recurse into the Rule of Three. It appears as a great dragon, eating her own tail. I'll just call the dragon Ouroboros because her name is probably 452352 letters long or unpronounceable. Her head is the Outer Planes. Sigil is the center of consciousness, and the Outer Planes correspond to her emotions (Elysium is her happiness and Gehenna is her ambition, for example). The Lady of Pain is her mind, and the Dabus are her memories. The astral is her neck, connecting to her torso, the Prime. The crystal spheres are various organs and such. The ethereal is her tail, ending in the Inner Planes, which is, you know, the spiky bit at the end of the tail. There are 7 spikes on hers. "But there are six elemental planes" you might say. The spire? That's just the seventh, core spike, appearing to poke through the Outlands because it is in her mouth. If you dig down under the Spire, maybe you'll reach the Ordial, or the plane of Elemental Quintessence, or the Macrocosm, or whatever. The wings are the Plane of Shadow. It connects alternate primes, because Ouroboros's wings touch her nearby friends' wings."
The Ouroboros
Yeah, I was inspired by that.
FUN FACT:
One of my ideas for the configuration was that the Inner Planes were the chest, with Water as the Heart, Fire as a gland, Earth as the ribcage and Air as the lungs. I chose not to after I couldn't think up of things for the quasi/para/energy elements.
THERE it is! Hah! On the quasielementals linked from that page. I've been looking for that reference for months. I'd been thinking it was on Ooze, but this mimir article has it placed on Clay, a semi-plane between Ooze and the Positive!
Man, I'm glad I finally found that again. Thanks, Rip!
The elemental associations of the various qi meridians in acupuncture might be a good mythical guideline for those, perhaps?
Ananake is another term for the Ouroboros, and was one of the first of the Protogenoi (the very first or second in some versions). I don't know if there's any canonical info on her, but if you go by Greco-Roman mythology and her portfolio, she definitely would have been borne out of the Ethereal (like Ptah in all likelihood) rather than the Astral. (for those unaware, Ananake is the Protogenai of inevitability, and yeah, I'd place her divine realm on the Ethereal. She might even be 'related' to Ptah, so to speak.)
That reminds me of this essay.