In Zoroastrianism, the sacred fire (adar) symbolizes righteousness and the presence of God. All prayers are to be said in the presence of fire.
The ancient Iranian veneration of fire probably has its roots in the hearth fire, which was kept continually burning. Sacred fires have been tended in temples since about the 4th century BCE.
A wood fire is kept burning continually in Zoroastrian/Parsi temples, which are known as "fire temples." The sacred temple fire is usually atop a pillar or in a metal container.
- Boyce, Mary, “Zoroastrianism.” Hinnells, John R. (ed.), The Penguin Handbook of the World's Living Religions (Penguin Books) 247-48.