. . . and thanks for your subsequent PM Mike.
OK, just pulled up a picture at random. This one isn't easy so I'll give a few clues from the outset. It's immediately inside the entrance to a short cave in the classic Three Peaks area, according to the Northern Caves guide. (So not, as it may look, a Northern Dales cave.) For scale, the passage here is just under a metre high.
If folk struggle I'll give more clues but if no-one gets it after a couple of days I'll tell you what it is and someone else can have a go.