Anybody know anything about the random vertical shaft behind Vox's Lair?

[uygi]

I started messing around looking for unreachable geometry in zones, like the "GM rooms", and I noticed this tall vertical shaft behind Vox. It's behind the door in the lair, at the end of the dead-end tunnel.

It's pretty tall, and it has a texture across the top. Anybody know any trivia about this, maybe at one time devs considered it might go to/from somewhere? Is it just to explain how the giants get in and out? Presumably that Priest of Nagafen goes home for holidays, and the regular entrance can't even fit an ogre, never mind a giant...