The religious buildings of ancient India may be chronologically classified under three heads: (1) the stupas, (2) rock-cut caves, and (3) structured temples. The Stupa was something of a burial mound or tumulus enclosing within it the relics of the respected dead.
It is commonly associated with Buddhism and Jainism, more particularly with the former; and Buddhist stupas have been found in many places in India, as also in Ceylon, Burma, Indonesia and China.
Stupas are of three kinds; Sariraka stupas enshrining bodily relics of particularly the founders of religions, Paribhogika stupas erected over the articles such as the begging bowl or staff of such persons and Pariyatrika stupas which were erected over spots visited by the founder or his disciples.
The most important part of the stupa is the hemispherical dome. It is surmounted by a square railing called harmika which encloses one or more shafts of the crowning umbrella. The dome is supported by one or more cylindrical or square plinths.
There are also railings enclosing the perambulatory passages. While the earlier stupas were just hemispherical with a low base the later stupas took a more cylindrical form. The decorative elements also were multiplied.
The South Indian stupas are characterised by the lion pillars at the gateways and the five ayaka pillars standing on each of the projections at the four cardinal points. The dome of the Ceylon stupas is bell shaped.
The cardinal points have architectural projections. They have rows of stone pillars, apparently for carrying a roof over the stupa. Besides, there are seen moonstones and figures of yakshas carrying a puranaghata.
The earliest examples of stupas in South India are found at Amaravati, Nagarjunakonda, Bhattiprolu, Jaggayapeta, Salihundam and a few other places.
The stupa at Amaravati was dismantled by a local zamindar in the last century but panels of stones containing sculptures were collected later and some of them are now housed in the local site museum at Amaravati while the others are now in the British Museum, London, and the Government Museum, Madras. The sculptures at all the places are either in marble or sandstone.