Has anyone ever tried to open a sinkhole to go caving?

Question

I have recently gained permission to open a sinkhole on a neighbors property. The sinkhole is around 5 feet deep standing in the center and around 15 feet wide. It doesn't really sound hollow at the center of this sinkhole but I'm expecting there to be a cave beneath this sinkhole. If any one has ever opened a sinkhole how deep did you have to dig before you broke through? I don't need any skeptics telling me not to because it's going to happen. I already have a good idea why it's there and what the dangers are and I'm up to it. So if you've opened one before and have some pointers hit me up. Thanks everyone.

Answer 1

Don't forget to anchor a rope and tie it around your waist. You will not know when or in which direction the cave (if there is one) will be, if it opens up under your feet, you will drop with a big "spelunk" sound.

Answer 2

Before you waste a ton of time digging, I recommend finding some geophysicists to come do a survey. It shouldn't take them long to figure out if there is a cave and about how deep you would need to dig to get to it.

(If the land owners have any buildings on the property, they may want to know if more sinkholes are going to be popping up anyways.)