Raindrops sliding off palm leaves, falling into the water tank below, make a ‘ding’ sound, as if bidding farewell to the owner of this place.,Many lessons can be learned from the saying that "things not kept secret will lose their value.",This city was called Dù Xià Chéng, shaped like a half moon, encircling the mountain where Tiāndū Shān Yù (Heavenly Capital Mountain Garden) was located.。