It was very much inspired by the library in Umberto Eco's The Name of the Rose. I liked the idea of a maze made up of rooms rather than corridors. I'd also have to say that it's also inspired by the castle in Ico. I wanted a dungeon made up of puzzles that the players could solve, rather than just smashing through monsters and relying on their stats to save them.

GM: "You open the door and come into yet another square room with tall stone walls. There is a sturdy iron gate in one wall, which leads down into a dark corridor filled with knee-high water, and lit only by a little sunlight coming in through square holes in the ceiling of the tunnel. The wall there is only about half the height of the rest of the walls, but it is too far up for anyone to reach, even if they jump."
Player 1 (playing Zeiksu): "Is the gate locked?"
GM: "It doesn't have any noticeable locks or handles, or even hinges now that you look at it."
Player 2 (playing Jez): "I'm gonna jiggle it. Does it move? Can I push it up or to the side or anything?"
GM: "It gives a bit if you move it upward, but not much. It's locked somehow."
Player 3 (playing Reya): What if Reya stood on Gambit's shoulders? Could she reach the top of the wall then?"
Player 2: "Gambit's a wolf...."
Player 3: "He's a big wolf."
GM: "No, it's still not enough height."
Player 2: "Hmm... hey, what does Reya weigh? Jez is pretty tall, could Reya reach the ledge if she's standing on his shoulders?"
GM: "Could be. Try it."
Player 3: (After climbing onto Jez's shoulders.)"Okay! Can I reach the chain now?"
GM: "Yeah, it looks like you can reach it now."
Player 3: "All right. I climb up."
GM: (After appropriate climbing rolls.) "Reya manages to get up without much problem. What she finds is another stone corridor. There is a stairway off to the left and a line of square grates in front of her, leading to a sharp drop into a dead-end corridor flooded with water about to knee height. There seems to be another stairway leading down into it, but also closed another iron gate."
Player 3: "Hmm... how big are the grates?"
GM: "About four by four feet."
Player 3: "Can I get one open?"
GM: (After appropriate strength rolls.) "She manages to get one of the grates open. Inside is the water-filled tunnel the group saw from the first room."
Player 3: "I jump down."
Player 2: "Great, now you can't get back out.... How much does Zeiksu weigh?"
Player 1: "What does Reya see?"
GM: "A water-filled corridor. In the middle, on either wall, there are pressure plates with magic symbols on them."
Player 2: "Traps!"
Player 3: "I'm gonna push one."
GM: "When Reya pushes it, the symbol glows blue and the gate to the water-filled dead-end opens."
Player 3: "Okay, I push the other one. Does that open the other gate?"
GM: "It does, but as soon as Reya's hand is off the first one, the first gate falls shut."
Player 1: "Keep the gate open so we can all come in." (They do that.) "Hmm... now, I'll keep the next one open and then... maybe you all can lower a rope to lift me out."
Player 2: "Reya should've taken a rope up in the first place!"
GM: "There was nowhere to tie it, and she's not strong enough to lift the guys."
Player 3: "Besides, how would Gambit get up?"
Player 2: "Okay, we do all that stuff Zeik just said."
GM: "Once they get Zeiksu out of the corridor, the stairway on the left is the only other place to go. As they approach it, though... is that growling they hear...?"