A Stupa is a dome-shaped sacred burial mound of brick that was used to house Buddha's relics, It is used to commemorate significant facts and events related to Buddhism . Sanchi, Sarnath, Amaravati, and Bharhut are among the oldest known stupas. Characteristics of Stupas Initially, mounds of Earth are encased in bricks. Stupas are usually built on a foundation laid with blocks of stone or bricks . On this foundation, a hemispherical dome was raised called Anda . Hence pair 1 is correctly matched. The drum of the stupa became more elongated and elevated . It took the form of a cylindrical vessel. On the truncated top of the hemisphere, a harmika is placed , surrounded by a railing. Hence pair 2 is not correctly matched. The stupa is enclosed by a vedika . At Barhut, Sanchi, and Amaravati the vedika consisted of upright pillars with three transverse bars known as the suchi . The railing is provided with four gateways. A path of circumambulation runs around the stupa at the ground level within the railing called Pradakshinapath . Toranas were ceremonial gateways around the stupas. Hence pair 3 is not correctly matched.