The Palace Museum of Beijing, formerly known as the Forbidden City, is the Royal Palace of the Ming and Qing dynasties in China. It is located in the center of the central axis of Beijing and is the essence of ancient Chinese Palace architecture. Beijing Palace Museum is centered on three main halls, covering an area of 720,000 square meters, with a construction area of about 150,000 square meters. It has more than 70 palaces and more than 9,000 houses. It is one of the largest and most complete ancient wooden structures in the world. The Beijing Palace Museum was built in 1406 in Yongle, Chengzu, Ming Dynasty. It was built on the basis of Nanjing Palace Museum and completed in 1420 in Yongle. It is a rectangular city pool, 961 meters long north and south, 753 meters wide East and west, surrounded by a wall 10 meters high, and 52 meters wide moat outside. The buildings in the Forbidden City are divided into two parts: the Outer Court and the Inner Court. The center of the foreign Dynasty is the Hall of Taihe, the Hall of Zhonghe and the Hall of Baohe, which are collectively called the three halls. They are the places where the national ceremonies are held. The center of the Inner Court is the Qianqing Palace, Jiaotai Palace and Kunning Palace, which are collectively called the Hou Three Palaces and the main palace where emperors and queens live. Beijing Palace Museum is known as the top five palaces in the world (Beijing Palace Museum, Versailles Palace, Buckingham Palace, White House of the United States, Kremlin Palace of Russia). It is a national AAAAA-level tourist attraction. It was listed as the first batch of national key cultural relics protection units in 1961 and as a world cultural heritage in 1987.