Mystery Valley is the single most visited section of Tianzhu Mountain, and the reason is immediately apparent: the maze-like corridor formed by massive fallen boulders creates an experience unlike any conventional trail. The route threads through 53 caves, tunnels, and passages over a distance of several hundred meters, passing through spaces that range from tight squeezes requiring a sideways approach to cathedral-scale chambers where the boulders overhead have stacked into accidental arches thirty meters high.
The lighting inside the cave system changes constantly as shafts in the rock admit narrow strips of sky or deflected sunlight. The pools formed by underground seepage reflect the rock walls and the fragments of sky visible above, and the sound of water in the deeper passages creates an atmosphere that justifies the name. Navigation is marked with painted arrows, but the trails split frequently enough that moving slowly and looking carefully remains the best strategy. Allow at least ninety minutes; rushing misses too much.