The guys at work are big-time spelunkers, and have been buzzing about a sinkhole dig over by Penn's Cave east of Centre Hall. They almost talked me into going along last weekend, until I remembered that what we were talking about was heavy labour in a muddy hole in early spring and decided to do, er, something else. Anything else. They came back on Monday very proud of their progress in cleaning out the big muddy hole. They have great hopes of it becoming a proper cave.
Did you know that many caves get that way by human intervention? Apparently it's a thing with spelunkers. They find likely sinkholes, and do a lot of digging & clearing & hauling to get the trash & rubbish out, & let the water flow through cleanly. The hope is that there are voids behind or below said clogged sinkholes, which once exposed could be explored by eager, very, very muddy spelunkers.
Well, it's a hobby. My comment was that mucking about in a cave with an active stream pouring into it sounded like a recipe for an underground drowning, and they assured me that this was what they had weather reports for. After all, we work with meteorologists, don't we?