Dravidian style temples consist almost invariably of the three following parts, arranged in differing manners, but differing in themselves only according to the age in which they were executed: porches or Mandapams, which always cover and precede the door leading to the cell. Gate-pyramids, Gopurams, which are the principal features in the quadrangular enclosures that surround the more notable temples. Gopurams are very common in Dravidian temples. Pillared halls (Chaultris or Chawadis) are used for many purposes and are the invariable accompaniments of these temples. Besides these, a temple always contains tanks or wells for water - to be used for sacred purposes or the convenience of the priests - dwellings for all the grades of the priesthood are attached to it, and other buildings for state or convenience.