This shows the classic Ming styling of the Temple of Heaven Park buildings and layout. You might notice the similarity between this structure and the earlier 13 Ming Tombs Gate.
The roof-line, the tile work on the roof as well as other decorative use. The arching entry. Not so obvious are the attention to numerology in the detail and the attention to the mythological layout of heaven and earth along the points of the compass.
The "Son of Heaven" would come here on auspicious occasions to pray for good harvests to feed his people, to seek divine clearance for decisions of state, and to atone for the sins of his people. Different buildings inside the grounds were for different purposes. Some of the citizens were allowed in for some of the rites, not for others.