User blog comment:IamJakuhoRaikoben/Chapter 372: Breach, Review./@comment-4449950-20140312110503/@comment-4449950-20140312113159

Well, Panda (who I don't think we ever trust and who left off the last page) said "in the great cave of Dokjelly Valley", which gives us two jelly-related translations so far, but yes, Chaos will likely have to come to the rescue XD

Cave and cavern as well as canyon and valley are pretty similar, so it's just the title that seems weird. Probably one of those multiple interpretation things :) As I said in my review though, poison jelly has been used in the series before, so it makes sense.