The ancient castles in Tibet and the traces of wind and moon can be found all over the world, but it seems that the ancient castles in Tibet in China are different from those in other places, because they not only keep watch over the years, but also keep watch over the gate of faith. Some of the high walls and big tiles experienced wind and frost are located on the cliff, and some are hidden in the mountain stream. The day is silent, and the night is full of old dreams. When I look at the snow mountain and blue sky in the distance, I know that every ancient castle has its own story.