The Palace museum used to be the imperial palace of the royal families of the Ming and Qing Dynasties in China. It was built in 1420. Located in the center of Beijing's central axis, it covers an area of 720,000 square meters and has a building area of about 150,000 square meter, with more than 70 palaces and over 9,000 houses. It is one of the largest and most complete ancient wooden structures in the world. It was listed as a world cultural heritage in 1987. Beijing Palace Museum contains a large number of precious cultural relics. According to statistics, there are 105,2653 pieces in total, totally 1 million pieces of cultural relics, including many priceless national treasures