
Robot_nachos |

The exact "locations" (and I'm using that term loosely mind you) of the planes are left slightly vague by design as to allow GMs wiggle room when building plots. However, there happens to be a concrete answer to your question in the gamemastering section.
the shadow plane is a transitive plane so here's the relative bit from that:
These three planes have one important common characteristic: each is used to get from one place to another. The Astral Plane (although technically an Outer Plane) is a conduit to all other planes, while the Ethereal Plane and the Shadow Plane both serve as means of transportation within the Material Plane, which they're connected to. These planes have the strongest regular interaction with the Material Plane and can be accessed using various spells. They have native inhabitants as well.
TL;DR: Material plane only unless otherwise stated by your GM.

![]() |

Well, the Great Beyond has the Shadow plane touching the Material, the Ethereal, the Negative Energy, and Positive Energy planes by page 5...
Page 12 starts in earnest to describe just what the plane of shadow touches; Ethereal, Material, Negative, Positive, Void. I would note that I have read in other areas of this book that it touches/borders on the Hells as well. (probably Caina and Nessus from the looks of the drawings) The First World also can be gotten to via thin inlets in the Shadow plane (and ethereal).
It notes that Shadow Absalom is a free gateway out of the plane of Shadow. (You unerringly appear exactly where you went in, even if thousands of miles away)
I think, but can't exactly recall, that you can get out of Pharasma's domain via the Shadow Plane as well...