with a second storey above; (3) Square temple with a low and squat sikhara
(tower) above; (4) Rectangular temple with an apsidal back and a barrel-
vaulted roof above; and (5) Circular temple with shallow rectangular
projections at the four cardinal faces.
                    ORIGIN OF INDIAN TEMPLES
  The important question here is who or what has contributed in the
  evolution of the Indian temple? Is it a single tradition or is it an amalgam
  of various traditions? It is believed by some that the temple form is
  derived from the Vedic altar, the earliest known sacred structure (vedi),
  which had the square as its essential form. However, many other origins
  are assigned to it by others with equal, if not greater, validity. Although
  from the Vedic altar to the Puranic temple, square remains the essential
  form, the temple seems to have no direct origin in any single tradition.
  When the Vedic religion of sacrifice (yajna) gave place to the Puranic
  cults dominated by bhakti (devotion) and worship of personal deities like
  Vishnu and Siva, the temple became the focus of every sphere of human
  activity. The temple, unlike the Vedic altar, does not accomplish its
  purpose by being built; instead, it must be seen (darsana). Art increases its
  importance and it becomes a holy site (tirtha). The purpose of visiting a
  temple was and still is to have a darsana of the temple, and to worship the
  divinity. Offerings and gifts (dana) have replaced the sacrificial tradition
  of old.
      Apart from the square Vedic altar, other non-Vedic, non-metaphysical
  and more historical beginnings are assigned to the temple. For example,
  the present-day flat-roofed shrine is commonly seen as an offshoot from
  an aboriginal prototype, the stone dolmen or a sepulchral (funeral)
  structure which first appeared in the megalithic age in the centuries
  immediately before and after the beginning of the Christian era. The stone
  dolmen was a small chamber formed by one large slab of stone, supported
  by three upright slabs set on their edges, with one side open to serve as an
  entrance. It could well have been the forerunner of the early central Indian
  Gond temples and the flat-roofed central Indian and south Indian temples,
  like the timeless varieties of village  and wayside shrines with their cubical