From trips that I did in there during the early 1980s I would say that more likely in the upper series it has at some point been, and very possibly still is, the best-decorated cave in Northern Europe. Others should be more informed as to the current situation.
Here's an extract from an interview that I did with Bill Gascoine: "I remember, I say I remember particularly that trip into Otter Hole: Jim Hay took me in Otter Hole when it was first discovered. It had only been discovered a few weeks . . . and I had a headache and it wasn't from the strenuousness of the trip. It was from constantly looking where to put your feet and where to stand up and where to duck down and where to be able to lean against a wall and not lean against a wall. It was one hell of a trip! . . . And I had a horrible feeling when I came out from there that I'd done irreparable damage through sheer ignorance . . . And I didn't like it at all and in fact the, the three people that were with me were all . . . we all sat in the pub afterwards and had the same view that 'God, that was hard work!' And it was hard work because of the sheer beauty of the place and having that feeling you really shouldn't be there." (Bill Gascoine, 1988)