The era of stone architecture in India seems to have begun with the reign of Asoka about 250 B.C. It is contemporaneous with the rise of Buddhism, whose followers gradually usurped the place formerly occupied by the Aryans. The Buddhist buildings then erected may be divided into three principal classes:
1st. _Topes_ or _Stupas_, with their surrounding rails and lats:
2nd. _Chaityas_, which, in form and purpose, closely resemble the early Churches of the Christians, though several of those cut in the rock were, in all probability, excavated before the Christian era: and,
3rd. _Viharas_, or Monasteries, forming in the earliest times the dwellings of the monks or priests who ministered in the Topes or Chaityas, but afterwards becoming the independent abode of monastic communities, who had chapels or oratories appropriated to their use within the walls of their monasteries.
We are here concerned only with the Tope or Stupa.
In its origin we suspect that it simply took the place of the mound or tumulus which the Turanian and other races had from earliest ages been accustomed to raise over the last resting-place of their dead. No such tumuli now exist in India, having probably been washed away by the tropical rains or river-floods; but some are still found in Afghanistan. The Indian type is distinguished from the tumulus of other countries by its material and its shape. It is built of brick or stone, in a rounded or conical form. It is distinguished also by the circumstance that instead of being the place of interment of a corpse, it is the depository of relics.
Besides being used as a relic-shrine, the Tope was frequently employed as a memorial tower to indicate a sacred spot. Of the 84,000 Stupas which, according to tradition, Asoka erected, fully one half would seem to have been raised to mark the scenes where Buddha or some Bôdhisatwa had performed a miracle or done something worthy of being remembered by the faithful.
The "rails," or stone-circles, surrounding the Indian Topes are often of as much importance as the Topes themselves; and in the case of Sanchi and Amravati, are even _more_ important. As with the Topes, they are sepulchral in origin. "The circles of rude stones found all over Europe certainly are so in most cases. They may sometimes enclose holy spots, and may possibly have in some instances places of assembly, though this is improbable. Their application to the purposes of ancestral worship is, however, not only probable, but appropriate. Sometimes a circle of stones encloses a sepulchral mound, as at New Grange in Ireland, and very frequently in Scandinavia and Algeria. In India rude stone circles are of frequent occurrence." Some hundreds are found in the neighbourhood of Amravati alone, and all are sepulchral; but like the Topes when adopted by the Buddhists, they were "sublimated into a symbol instead of a reality."