The Forbidden City, located at the centre of Beijing, was the imperial palace of China for five centuries, until the early 20th century. It today houses the Palace Museum, one of China's largest national museums, with an extensive collection based on the former imperial collection. This is truly the spot to appreciate the might and grandeur of the Imperial Chinese court during the height of its power in the Ming and Qing dynasties.
The Forbidden City is a very big place with lots to see: a typical visit covering the main palace buildings and the main museum displays will usually take a full day. If you are pressed for time, consider focusing on only the main halls and just a couple of the museum sections.
According to UNESCO, the Forbidden City is the largest collection of ancient wooden buildings in the world.