Both the Altar of Praying for Harvests and the Altar of Circular Mound are surrounded by cypresses, symbolizing "the blue round jade piece used to pay homage to Heaven" expounded in the "Rituals of the Zhou Dynasty." In the temple there are nearly 4,000 century-old cypresses (The oldest, planted during the Jin Dynasty -1115-1234) are about 800 years old) and they are, therefore, precious cultural relics. The cypresses around the Altar of Praying for Grains are mostly oriental arborvitae while those around the Altar of Circular Mound are Chinese junipers. The huge ancient trees create a magnificent and solemn atmosphere typical of sacred altars.