Fire temples are graded — the highest, the Atash Behram, requires fire gathered from sixteen sources including lightning and a cremation pyre, purified through a process taking a year or more. The fire is never allowed to go out, is fed sandalwood five times daily by masked priests, and non-Zoroastrians are generally not admitted to the inner chamber. Nine Atash Behrams exist in the world, eight of them in India.