Thanks a million for the feedback. The white at the entrance is a bit too white to be honest. I tried to recover detail from it but was struggling so I decided to go in the other direction. I agree that it does look HDR but it is one shot. It wasn’t the most interesting picture originally so I suppose I have ventured into surreal territory with my adjustments, but had I not I don’t think I would have ever gone back to it.
Thanks once again for your feedback. Much appreciated.