Old Man's Cave is a training ground for Veni-Yan monks. In the old days when the Kingdom of Atheia was still strong the royal family would be trained at Old Man's Cave in Dragon lore and the lore of The Dreaming. When the war broke out Gran'ma Ben relocated to Old Man's Cave to prepare. It is known that this is where Rose and Briar Harvestar did some of their training.
Out From Boneville
Eyes of the Storm
When Lucius, Phoney, and Smiley are pursued by rat creatures while trying to get to the Barrelhaven Tavern, Smiley, who is driving the cow, thinks it's a good idea to ride off the cliff of Old Man's Cave. Obviously, this is not. Luckily, they land in a river to break their fall, only to be drenched by a rainstorm a few minutes later.
Old Man's Cave
Obviously, this book is named after Old Man's Cave. This is where most of the action takes place in.
When Thorn, Wendell, Jonathan, Phoney, and Euclid are found by Veni Yan Monks, they tell her to go to Old Man's Cave. Unsure what she should do, she wants to stop for the night. She later decides to go find Fone Bone instead, thinking that she cannot trust her. Later, Fone Bone and Smiley Bone convince her that she should trust her grandmother.
Wendell, Jonathan, Phoney, and Euclid are taken to Old Man's Cave by Gran'ma Ben. There, Gran'ma Ben tells Phoney about the beginning of the world, according to their religion.
In ghost circles, all of the farmers and monks that survived the explosion stay there until the end of the book, when Lucius suggests that they go to Atheia.
Crown of Horns
In the sixth chapter of the book, there is a reference of the bones, Thorn, Bartleby, and Gran'ma Ben staying at Old Man's Cave to pay their respects to people that died there.