The Forbidden City was constructed from 1406 to 1420, and was the former Chinese imperial palace and winter residence of the Emperor of China from the Ming dynasty (since the Yongle Emperor) to the end of the Qing dynasty, between 1420 and 1924. The Forbidden City served as the home of Chinese emperors and their households and was the ceremonial and political center of the Chinese government for over 500 years. Since 1925, the Forbidden City has been under the charge of the Palace Museum, whose extensive collection of artwork and artifacts was built upon the imperial collections of the Ming and Qing dynasties. The Forbidden City was declared a World Heritage Site in 1987.

The complex consists of 980 buildings, encompassing 8,886 rooms and covering 720,000 square meters. The palace exemplifies the opulence of the residences of the Chinese emperor and the traditional Chinese palatial architecture and has influenced cultural and architectural developments in East Asia and elsewhere.

The Hall of Supreme Harmony is the largest and rises some 30 meters above the level of the surrounding square. It is the ceremonial center of imperial power and the largest surviving wooden structure in China. It is nine bays wide and five bays deep, the numbers 9 and 5 being symbolically connected to the majesty of the Emperor. Set into the ceiling at the center of the hall is an intricate caisson decorated with a coiled dragon, from the mouth of which issues a chandelier-like set of metal balls, called the “Xuanyuan Mirror”. In the Ming dynasty, the Emperor held court here to discuss affairs of state. During the Qing dynasty, as Emperors held court far more frequently, a less ceremonious location was used instead, and the Hall of Supreme Harmony was only used for ceremonial purposes, such as coronations, investitures, and imperial weddings.

The Forbidden City is surrounded by a 7.9 meters high city wall and a 6 meters deep by 52 meters wide moat. The walls are 8.62 meters wide at the base, tapering to 6.66 meters at the top. These walls served as both defensive walls and retaining walls for the palace. They were constructed with a rammed earth core, and surfaced with three layers of specially baked bricks on both sides, with the interstices filled with mortar.

At the four corners of the wall, sit towers with intricate roofs boasting 72 ridges, reproducing the Pavilion of Prince Teng and the Yellow Crane Pavilion as they appeared in Song dynasty paintings. These towers are the most visible parts of the palace to commoners outside the walls, and much folklore is attached to them. According to one legend, artisans could not put a corner tower back together after it was dismantled for renovations in the early Qing dynasty, and it was only rebuilt after the intervention of carpenter-immortal Lu Ban.

It is listed by UNESCO as the largest collection of preserved ancient wooden structures in the world. Since 2012, the Forbidden City has seen an average of 14 million visitors annually and received more than 19 million visitors in 2019. In 2018, the Forbidden City’s market value was estimated at 70 billion USD, making it both the world’s most valuable palace and the most valuable piece of real estate anywhere in the world.

According to Wikipedia