United States of America
(580 ft/177 m). Named for the bones of antelope and mountain goats, bighorn sheep skulls, and two human skeletons discovered inside. It is a remnant of two very large lava tubes, one on top of the other. This allows cold winter air to be trapped inside and create a year-round ice floor on the lower
level, accessible via a smooth trail and down a metal stairway to a platform.
Listen to the audio guide for Skull Cave Free on WIP — starts by itself when you arrive, even with the screen off