Here are two more pictures taken in Jiuzhagou, China.
I must admit that they illustrate more of serene scenery than mere boundaries.
Somewhere between the lake and the temple must be a boundary – a boundary which is hidden by the fact that there is a fall between them.
In the second picture, there is a definite boundary – a timber fence which separates the visitors from the hills and lake below.
Mentally, the boundaries are just invisible, as you have become immersed in Nature!