Aenwyn, you notice that the corridor is not only clean, but almost too clean. Especially compared to what you saw in the other one. You don't notice anything at all on the walls, floor or even the ceiling. Not a single speck of dust or anything else. Clearly something or someone comes this way often and cleans very thoroughly. And as you check everything, you notice the walls. Not just the walls. Again, the floor and ceiling, too. They're not of any kind of material you know of. Not wood or stone or metal or bone or anything else. You try knocking on them, but with no idea of what it's supposed to sound like, it's hard to tell how thick the walls are. They're probably quite strong, though. One thing that you do notice, though, is what seems to be a map on the wall. It's faint in the places that you can see and missing sections, but from what you can tell, the tower is mostly laid out in concentric rings of corridors, linking larger rooms. There's at least two entrances from the outermost ring to the next outer one and various inner ones. There seems to be a few ways up or down, distributed apparently at random, with a bigger one right in the center.