Originally posted by AugustusKron:

the RNG dungeons are interesting, but they can really be disappointing.. i actually found a Sunken Crypt with only 1 pile of muddy scrap in it.. it was pretty much right next to a Bonemass and nothing but dead ends..

of course the very next crypt i found had 150+ iron in it, so it sort of made up for it

You didn't say which game so I am going with this lil known cave system in World of Warcraft vanilla at the far end of Sillithus that has no use or mobs or anything, it's just a named cave with no use at all. Microbes would be bored in it.