One small correction to your post, bloonewb: you wrote
[QUOTE=bloonewb]Through twists and turns they traveled, in grey stone spaces leading this way and that, barely illuminated unlike the previous hall.[/QUOTE]

I was confused for a moment reading this until I considered my own post, and realized how my description of the area might be difficult to grasp just from a verbal description. I'm guessing that the "twists and turns" mentioned refers to what I wrote here:
[QUOTE=Dark Jack]What awaited them on the other side of the doors, however, seemed like a completely different world than where they had just come from. The door opened onto a stone walkway running left and right before them, about as wide as the hallway behind them, with a small drop to the side opposite of them. The stone walkway reached a dead end at a wall to their left, whereas to their right it made a left-turn, following what seemed like the top of the actual Grand Cathedral, with part of the wall there being an actual mosaic window beyond which the cathedral interior could faintly be seen. At the opposite end the walkway made another turn, this time to the left, forming a sharp U-shape around the central area below the walkway, reachable by several sets of stairs, one of which was right in front of them.[/QUOTE]

This doesn't actually describe a hall, but a walkway that only has a wall on the outer side of it, whereas it is open on the inside facing towards the central area. The area I was trying to describe is actually the [url=https://bloodborne.wiki.fextralife.com/file/Bloodborne/uppercathedralward.png]Lumenflower Gardens[/url] (best image I could find to show its layout; its the one in the middle left of the map, with the Celestial Emissary) from the game, only entering from the opposite side of the garden and with two additional stairs built to allow access to the central garden. No twisting or turning necessary; the moment Morgraine and Dietrich left the long, straight hallway, they would be right above the garden.