is used for temples of any of the deities of polytheism. Other terms include diàn which indicates the "house" of a god, enshrining one specific god, usually a chapel within a larger temple or sacred enclosure; and tán which means "altar" and refers to any indoor or outdoor altars, majestic outdoor altars being those for the worship of Heaven and Earth and other gods of the environment. Gōng, originally referring to imperial palaces, became associated to temples of representations of the universal God or the highest gods and consorts, such as the Queen of Heaven. Another group of words is used for the temples of ancestral religion: cí (either "temple" or "shrine", meaning a sacred enclosure) or zōngcí ("ancestor shrine"). These terms are also used for temples dedicated to immortal beings. Zǔmiào ("original temple") instead refers to a temple which is believed to be the original temple of a deity, the most legitimate and powerful. Táng, meaning "hall" or "church hall", originally referred to the central hall of secular buildings but it entered religious usage as a place of worship of the folk religious sects. Christianity in China has borrowed this term from the sects. Guàn is the appropriate Chinese translation of the Western term "temple", as both refer to "contemplation" (of the divine, according to the astral patterns in the sky or the icon of a deity). Together with its extension dàoguàn ("to contemplate or observe the Dao"), it is used exclusively for Taoist temples and monasteries of the state Taoist Church. Generic terms include yuàn meaning "sanctuary", from the secular usage for a courtyard, college or hospital institution; yán ("rock") and dòng ("hole", "cave") referring to temples set up in caves or on cliffs. Other generic terms are fǔ ("house"), originally of imperial officials, which is a rarely used term; and tíng ("pavilion") which refers to the areas of a temple where laypeople can stay. There is also shéncí, "shrine of a god". Ancestral shrines are sacred places in which lineages of related families, identified by shared surnames, worship their common progenitors. These temples are the "collective representation" of a group, and function as centers where religious, social and economic activities intersect. Chinese temples are traditionally built according to the styles and materials (wood and bricks) of Chinese architecture, and this continues to be the rule for most of the new temples. However, in the early 20th century