Though I would delete "acquire rare or precious rocks" except, like the species, as carefully recorded samples for genuine scientific study.
Apart from your chances of actually finding anything "rare or precious" in a collection sense being extremely slim anyway, it's bad practice simply to collect or acquire anything gratuitously even if common. We just don't do it!
Oops, Sorry! I should have worded that better, by using "omitted" not "deleted" - if I'd written it.
I didn't mean you to do that because it now leaves a rather odd reply!
Most caves don't have "rare or precious rocks" for basic geological reasons, but many do have beautiful stalactites and related calcite formations, and though these can be very vulnerable to damage, we try to leave them as intact and clean as possible.
I've been in caves formed in striped marble, and exploring some of these is like being in a giant mint humbug!
I've also visited old metal-ore and building-stone mines, and these sometimes hold interesting relics. One of the latter has some calculations written in pencil on the wall by a quarryman in the 19C. Presumably calculations of stone yield, their method foxed cavers for a long time, but I think someone has now established the technique.
Actually, I did work for the sewer department and did get sent down the manholes a lot. Don't know if it was because I was the smallest guy on the crew or because I was a seasonal worker. :) I put manholes in quotation marks only because I can't remember if there is a more accurate term for a manhole other than manhole.
I truly did not mean to be funny up there - - but your take on my comment up there is funnier than what I had intended. And now I'm getting all worked up, ha! Yeah, I know, it doesn't take much. :)
Its not rocket science actually ,as over the years most people have come to the conclusion that it's far easier and safer to climb down rather than taking the quickest route by falling... Now someone say all real blondes are dumb ....:)D