Associated but that's something I never understood Rob. Radon gas causes lung cancer so we are told and gets into our homes as it leaks from the ground. So wouldn't living in a cave have even worse risks?When you buy a house, you normally have a survey and lots of form. These usually include a detailed description and I find it very difficult to imagine buying a cave home, where you live in them but have no idea what the rock actually? A cave home is so unusual that any purchaser spending this kind of money would want to know the structural properties before they stick their kids in, or before they breath in outgassing from some rock. I just cannot imagine not knowing that my house is made out of mainly brick, but with some block and tile. Something is wrong here. PS, my phone from the 90s could take photos and had a light, they have been able to take pics ever since.
Then you have this.