Yep. Many, many caves in Texas, and Mammoth cave in Kentucky. One of my first memories is of my dad holding me up over the railing and dangling me by my arms above this deep, bottomless pit in a cave that the guide had just finished describing - they'd demonstrated its depth by dropping something down the pit to show you couldn't hear the item hit the bottom. I wanted to scream, but I was too scared to make a noise. I was certain he was going to drop me until Mom told him to stop it and he pulled me back over the railing and set me on the ground. I felt naseously sick and Mom had to pull me to my feet to follow the group because I was too scared to stand back up. I am terrified of heights now, but not of caves, thankfully.
