The ones in the cistern are strangely more normal than the ones in the graveyard. They have definite death dates on them, and most are relatively recent (last 100 years or so).

Deeper into the cistern things get pretty weird. If you go in one direction, straight ahead from the stairs, after about a mile of floating along the skeletons become more and more present. If you keep going, there are more and more of them. You've found a mass grave. These skeletons are in various states of decay. The ones on top are less destroyed, but they are all slowly sinking into the acid and getting eaten by it.

Should you continue, strangely enough you find yourself back by the stairs.

Should you go to the left of the stairs, time and space start to distort after about a mile and a half. It's subtle at first, but then things start to flitch and change, and the cistern changes colors and the arches become strange and distorted. The stone is flesh, then stone again. However, as soon as things start to distort, the flesh bugs become agitated and more violent. They attack ferociously. Should you continue, you find yourself back at the stairs again.

Should you go any other direction, there is nothing of note.