China's largest temple and altar complex, the Temple of Heaven in the southern part of Beijing covers an area of 270 hectares. The Temple of Heaven is an exquisite and extraordinary example of Chinese religious architecture. Construction of the temple began in 1420 and at the temple emperors of the Ming and Qing dynasties worshipped heaven and prayed for abundant harvests. In imperial times, twice a year a magnificent ceremony was conducted when over 1,000 eunuchs, ministers and courtiers would leave the Forbidden City for the Temple of Heaven. The emperor would fast and remain celibate and sleep overnight in the Palace of Abstinence (zhaigong) before carrying out traditional ceremonies and sacrificial rites in the morning.