Well when you walk the trail to get to the caves , were high on the mountain , and we go down the 3/4 of a miles until we get to the caves. so its pretty far down ! as far as going far enough , you can go in one end and come out the other. then walk 15 minutes to the next cave. The quick sand like mud , I don't know how much was there , I wasn't trying to investigate after I had already sank once , lol but looking at it , there seemed to be a lot. I just walked where I could see sand or concrete from the cave itself. They have several more caves we can go through but Chevy isn't old enough to go through them and not sure my husband or I can do those because in some parts you have to crawl through them , and were kinda old for that. lol