Note the pear-shaped character of this passage in Sunshine Lava Tube. A congealed lava flow covers the center of the passage. The dark areas along the side are pathways coated with smaller cinders for easier walking in the caves.
The URL is: https://gotbooks.miracosta.edu/gonp/labe12/6/2010/html/lava196.htm
Last modified: 12/6/2010