Youxi Valley, literally Quiet Creek, is originally a part of the Cryptogam Collection which consists of three valleys in total, including Jingyi Valley (Peaceful Valley) and Xiaoyao Valley (Leisure Valley). It simulates the environments of wet, humid and semi-humid respectively, for the conservation of local and introduced ferns and bryophytes. A zigzag trail (Tree Fern Walk) crosses Youxi Valley starting from the Tree Fern Pond to the Palm Lawn. Half of the trail is stone, half steel grating. The steel grating is designed to leave the natural habitat unobstructed and provide an ecological corridor through which small animals can pass freely. On the lower end of Youxi Valley, you will see an open and flat ground, Secluded Moss Garden, where mosses grow abundantly on the ground, pondsides, rocks, and tree trunks and create a scene of tranquility and filling with rich feeling of Zen.