View from inside Vault Cave, a rarely visited lava tube in the Medicine Lake Volcano area of Northern California.  The cave has a couple of entrances & skylight openings.  The upper portion of the cave is only a couple hundred feet while the lower section is about 1,500 feet in length w/ one low crawlway section that opens up again into this large pristine passage.  The surface isn't that far up as one can see dangling roots from the ceiling.