Hey, I just found out that if you like put a lava block somewhere and die in it, and say /back you will come to a cave under it or something that is under. I'll do an tutorial so you understand it: First make a square so that you can fill the middle (1 block) with lava. Then make sure you don't have anything you don't want to lose. Then hop in the hot tub Next step : You HAVE to have /back command. Say /back POOF you are in the lowest cave / hole under the lava.
