I’ve made many trips into Coach Cave near Park City Kentucky. Coach was once a commercial cave (no longer) and has about four and a half miles of passageways. To get to most of the non-commercial part requires traversing a 2500’ passage called Spring Avenue. It starts out being seven feet high and is about 20’ wide the entire length. However the floor gradually rises and by the 1500’ mark, you’ve had to do a couple of short hands-and-knees crawling sections. For the last 1000’ feet, the highest point in the passage is 27” high, and the first 400’ of that is only 14” high. Still wide though. We have four aluminum snow saucers there with short lengths of rope attached. You throw your pack on one and tie it to your ankle and drag it behind you. The floor is covered with little round rocks that make it easier for the saucers to slide.
After you leave Spring Avenue you can walk for 50’ before you have a choice of two different hands-and -knees crawls, one 500’ long the other 700’. (Reaching the 500 footer requires a harnesses and vertical gear and jumping across a 25’ drop while rigged into a rope)
I’ve told people that to reach the most remote part of Coach is not especially physically hard - the cave is dry, 55 degrees F, no wetsuit, rope or climbing gear needed - most of the way if you want to take a rest you’re already lying down. You just have to tell yourself that it’s OK that for most of the next 10-12 hours either the wall, ceiling or floor is going to be 6-8” from your face. 😀
The reward for all this is often you get to see things of great beauty that few others do and sometimes you get to go places no human being has ever been.
Back in 1995 in another cave not far from Coach our project got to do both. We found a virgin passage (never before seen by humans) that was bigger than 25’x25’ for over a mile and in the middle half a mile you couldn’t see the limestone ceiling and walls because they were completely covered with a beautiful pure white gypsum crust with literally millions of gypsum flowers as much as 12” long. In many places they had repeatedly broken off of their own weight and piled up on the floor. Our next trips after the initial discovery we laid down a three foot wide trail with flagging tape and don’t allow anyone to go off trail for any reason. It’s one of the most spectacular passages in the US. Due to the combination of tight crawls and vertical rope work required, probably less had 200 people have ever seen it.