A cella (from Latin for small chamber) or naos (from the Greek ναός, "temple") is the inner chamber of a temple in classical architecture, or a shop facing the street in domestic Roman architecture, such as a domus. Its enclosure within walls has given rise to extended meanings, of a hermit's or monk's cell, and since the 17th century, of a biological cell in plants or animals.
In Ancient Greek and Roman temples the cella is a room at the centre of the building, usually containing a cult image or statue representing the particular deity venerated in the temple. In addition the cella may contain a table or plinth to receive votive offerings such as votive statues, precious and semi-precious stones, helmets, spear and arrow heads, swords, and war trophies. The accumulated offerings made Greek and Roman temples virtual treasuries, and many of them were indeed used as treasuries during antiquity.
The cella is typically a simple, windowless, rectangular room with a door or open entrance at the front behind a colonnaded portico facade. In larger temples, the cella was typically divided by two colonnades into a central nave flanked by two aisles. A cella may also contain an adyton, an inner area restricted to access by the priests—in religions that had a consecrated priesthood—or by the temple guard.