A short one, from my student days. I was, for reasons not really relevant to the story, attempting to write a guide to all the pubs in Birmingham. Yes, that was a bit much to attempt. It was intended to be a guide we'd sell to raise money for charity, through RAG. I couldn't go to every pub myself, and a couple of friends were helping out. They mostly brought back pretty useful information on each pub they went to, but for one, their report/review only read "Interesting entrance". They didn't seem to want to elaborate, and since they were doing me a lot of favours with this project, I didn't push. I just finished the guide with that entry for the pub, and published it. I finally tried to push them a bit more on what that entry had meant, assuming maybe the doorway was a big elaborate arch, or a bit hidden in an alley or something. They still wouldn't explain, but said they'd take me there to see. It was bricked up. Long closed. Plants growing through the wall. On the plus side, very few copies ever sold, so it's unlikely anyone was misled.