There are no endermen dungeons
I realize that, it's just that I've seen them a few times, but as I said, it doesn't neccesarily mean anything since they'll teleport to a dry area when it rains.
Edit: Well, I've found SOMETHING all right. Investigation currently in progress.
I looked at F3 and the usage graph is spiking like crazy, also the coords are -741, 1184
Edit2: Hmm, abandoned mineshaft, now this is getting interesting, still don't know whats causing the lag to spike.
Edit3: It dead ends, but it breaks into a deep cave, or a shallow ravine, not sure.
Edit4: I think I may have found the lag problem, there is a big lava lake below. I stashed all of my stuff and went on a suicide run in there, so at least there isn't anything lost in there.