Cave of Ether is the “cavity of a rock” where Ether hid after people “cast him out.” By day he hid there, and by night he went forth “viewing the things which should come upon the people” (Ether 13:13-14).
Ether made the remainder of his record while he dwelt in the cavity, viewing by night the destructions that came upon the people (Ether 13:13-14). In the first year he lived there, many people were slain while fighting against Coriantumr for the kingdom (Ether 13:18).
When people sought to kill Ether, he fled from them and “hid again in the cavity of the rock” (Ether 13:22).