The locals told me there were lava tubes in the area that you could hike into. They cautioned me that you could get lost in there so be careful. By asking around, I found one that I could drive to on my 50cc (small) Tohatsu motor bike.
I spotted the hole in a lava field not far from the road where the ceiling of the lava tube had fallen in and created a mound that you could walk down to get into the tube. I walked carefully in to the dark tunnel on the rough ground. I was exploring and eventually I could see some faint light further down the tube. This encouraged me to keep going to see what it was. After more careful hiking I came to a mound of lava where the ceiling of the tube had caved in. the mound was too small to climb up and out of the tube even though I could see the sky.
It was exciting and fun but I realized the only way out is to go back. So I quit hiking any further and replaced my route.
Written 2014 about a trip in 1962 (c) 2016 John A Peters 415-239-5393 Text/Cell