The Clock Exhibition Hall is one of the unmissable highlights of the Forbidden City. Located in the Hall for Ancestral Worship (Fèngxiàn Diàn), the exhibition hall houses about 200 clocks and watches of different kinds, both domestic and foreign from the 18th century. Time pieces in China have a long history. Before the Qing Dynasty, sundials and clepsydras were the main timepieces. At the end of the Ming Dynasty or the beginning of the Qing Dynasty, mechanical clocks began to be introduced into China. In the eighteenth century, mechanical clocks were widely used in the imperial palaces. While reckoning time, these clocks brought motion to their decorative people, birds, and flowers. Those clocks and watches were not only useful timekeepers, but also pleasing entertainment and exquisite craftsmanship.