Suppose, given the forum, it is likely that caching takes precedent over spelunking. I do, however, offer my services as a guide to any who wishes to pass through The Narrows from Ronan's well (Chilean Miner Rescue) into Robin Hood Cavern (near Amphitheatre)...
I'm keen to do this route sometime (and explore other caves in the area) - how long do the narrows take (assuming nobody gets stuck? )
Oh boy... Would I love to do (attempt) that!!! Trying to make a plan to be there (will mean driving back from Matroosberg on Sunday am).