Picture one through nine, and the panoramic, continue moving through the lava tube.
Lava tubes are formed when the lava flow develops a continuous hard and "crunchy" crust, which thickens and forms a roof above the still-flowing lava stream below.
This tube involved about a mile of walking and crawling through the cave which appeared to be as high as 10 feet and as low as about two to three feet, such as in pictures eight and nine.
Picture four and five shows the very smooth lava flow occuring under the rocky lava above.
Picture seven shows some unusual Norse symbolic writing on the walls. I believe the message translates "Get me out of here!".