China - Juizhai Valley National Park, Tibetan Flag Structure in Pengfengcun

Though I had no idea what the significance is of this structure, the way it was made and how it looked against the mountain backdrop was captivating.  It was big, and obviously a big deal to the Tibetans, but I wondered whether there was a purpose to the ragged flags that partially make up its roof.  Are they replaced once in a while?  Are they prayer flags or what?  Regardless, think it makes a pretty good picture...