I'll start this topic.I loaded up this one, old world that I made from Beta 1.7.3 in 1.5.2. So, after a bit of exploring, I found some permanent chunk errors. A while later, I found-what at first-seemed to be a jungle temple. However, when I looked around, it was only 4 blocks thick, and I also saw some little "portholes";3 of them had chests, 1 of them didn't. After robbing the chests (one had an enchanted book), I then decided to explore the top of the strange structure, but it was just empty. I then decided to set off in one way, and left the mossy structure for something else. I stumbled upon more strange structures, like Desert Towns/Pyramids, and a lonely village. What I mean by that is that there was only one building there; a church tower, with one villager. There were a few farms and a well, but that was it; other than a few more permanent chunk errors and that was it.