So, as the title says, this is a thread to talk about all the horribly generated and broken Adventure Maps you've played on!
Don't hesitate to talk about any horrific embarks too!
I'll start.
The second time I played Adventure Mode was on a horrible laptop, which could hardly handle the generation process of the world. So, I start my adventure, with an unusual loading time. So eventually I'm doing quests and exploring, until I got attacked by a lion. I killed it and kept walking north, until the map REALLY started to go apeshit on me. To my surprise I see a massive flood of lava coming towards me and I started running like crazy, around the lava "circle". As I walked around it, the ground started becoming lined with strips of Underground Cavern soil, and shrooms, and I WTF'ed. About 5 minutes later, I started seeing huge holes in the ground with lava flowing down it and parts of underground caverns just hanging everywhere. I honestly thought the world was collapsing at that point. Anyway, as I continued exploring around the poop generation, I noticed the map got dark and underground cavern-style the more I went north. So I did that, and eventually I saw no lava, only huge holes with strips of underground cavern soil making thin bridges above them. I was navigating through the place until I saw the holy artifact, Adamantine. Of course, I got the message "Adamantine! Praise the miners!" in a big box at the top of the screen when I saw the adamantine, and I LOL'd. Of course, eventually I got killed by a forgotten beast somehow.
So, post your broken adventure maps that you've played on here!