One of the most dominant characters of Buddhist architecture is the dagoba (stupa) dotting everywhere on the Island. In a shape of dome, often painted in white, the dagoba enshrines the Buddha's relics such as hair and tooth; it is usually constructed with bricks which are covered with plaster. This form of structure is firstly introduced into Sri Lanka at the same period of Buddhism's introduction into the island.

The tradition of building the stupas to enshrine the Buddha's relics originated during the reign of Emperor Asoka of India who sent Buddhist missionary, Mahinda, his son to Sri Lanka; it then spread out, there emerged numerous dagobas on the island. The early simple shape of the dagoba developed to six significant shapes that can be seen nowadays: bubble shape, bell shape, pot shape, the heap of paddy shape, and amalaka shape.

The vatadage is also predominant architectural heritage of Buddhism in Sri Lanka; it is a circular relic house enclosing a small dagoba with wooden roof and Buddha images on the four cardinal directions. Traces of this structure can be seen in Anuradhapura and Polonnaruwa today, but the wooden parts disappeared long ago.