As it's found in Volcano National Park, the park service has the first hundred yards or so of this Lava Tube lit. When we arrived, there were dozens of people rambling through the lit portion, their voices echoing off the stone walls, filling the tube with the clutter of too much conversation. We walked the tube, did tour with the other tubers and then continued on past the lights, around a high fence with a half-broken warning sign and into the real depths of the Lava Tube. Since not many people bring flashlights, few continue past the lit area, but it's back there that you really get a feel for the place. We walked all the way to the back where the tube gets smaller and smaller before it finally ends in a little bubble of a cave with a very low ceiling. We turned off the flashlight and sat in the pitch black listening to the water drip from the roof of the tube. It was mostly calming, though the darkness did make me a little claustrophobic. On our way back out we encountered another small group making their way through with flashlights and I was able to get some interesting long exposure shots.
Group with flashlight approaching. I didn't bring a tripod so I ended up setting the camera on a large boulder, a small piece of which you can see in the lower right hand corner. 100sec./f4.5/iso400
Group with flashlight retreating. (there were only about three or four people in the group even though it appears there are more because of the long exposure). 30sec./f3.5/iso100