Ah so it's almost a leader based system?
Would be interesting to go there I think. Perhaps a sign within the cave saying why the gate is there within the cave and how to get access past could be a good way of enticing people into the sport. Perhaps also with some information about how to get into caving, and find a local club etc.
Plenty of people walk past and go in, with that level of intrigue surely they're potential cavers.
Just seems a shame to have a massive plain gate with no evidence provided as to why it's there.