There is plenty of room to accommodate all the activities that take place here everyday.
Many people come here for exercise or to take free lessons in dancing, music, and playing games. One woman sang in a
Some people just did their own thing.
The complex was visited by the Emperors of the Ming and Qing dynasties
http://en.wikipedia.org/wiki/Temple_of_Heaven
The Temple of Heaven is the most holy of Beijing Imperial temples. The temple of Heaven was where the Emperor came every winter solstice to worship heaven and to solemnly pray for a good harvest. Since his rule was legitimized by a mandate from heaven, a bad harvest could be interpreted as his fall from heaven's favour and threaten the stability of his reign. So, it was not without a measure of self-interest that the Emperor fervently prayed for a very good crop.