The shelter offers a dexterity course everytime when there is a full moon (because the moon makes the atmosphere better). The main discipline is to remain unwobbling for quite a long time. The giant likes it as it makes him feel young.

Yung is composed of 庚 kêng to change, as phonetic, with 用 yung to use, as radical, which in turn was composed of 卜 pu to divine and 中 chung the middle. "Get your middle," says one luminary of the 1st cent. A.D., a not unworthy prototype of the famous Mrs. Glasse, "and then you can use it." It originally meant to use; hence the method to be used or followed, a course. [The Chung Yung is a short philosophical treatise in one section of thirty-three chapters. Its title has been rendered by Legge as The Doctrine of the Mean, by Julien as L'Invariable Milieu.]