A view at the bottom of the entrance to Big Cave near Fall River Mills, California.  This lava tube is accessed through a deep collapsed sink & has high ceilings & is all breakdown, going only a couple hundred feet in either direction.  The cave (as well as nearby Popcorn Cave) were more popular in past decades however access to them has been left unmarked & overgrown in a buckbrush/ghost pine setting.  Both caves have abundant coralloids.  Big Cave has a couple ferns at the entrance & frogs can be found at the entrance living in their own microclimate.