The Spirit Glyph Area
The Spirit Glyph area is the only Glyph area to have been (mostly) removed from Soul Reaver before the game was released, along with The Spirit Glyph itself.
Early prototypes of the game include this area near the entrance to The Turelim Clan Territory, where a small cave containing a campfire is located in the final game. These prototypes make clear that the Spirit Glyph area was actually repurposed into the health powerup area hidden in the Citadel, with the Spirit Glyph pedestal being covered with a fountain.
The Spirit Glyph area was nearly as small as the Force Glyph area. The reason for its deletion seems to have been its dependence on the deleted Possession ability. Perhaps as an homage to the Spirit Forges in Blood Omen, the solution to this puzzle seems to have required that Raziel possess a vampire and send them to the Spirit Glyph pedestal for sacrifice. Without that ability, the Spirit Glyph puzzle would have required a ground-up redesign.
The Deleted Forges, Reavers, and the Spirit Glyph video includes footage of this area.