Thera Mahinda, an envoy sent by King Ashoka himself introduced Theravada Buddhism and also chetiya worship to Sri Lanka. At his request King Devanampiyatissa built Thuparamaya in which was enshrined the collarbone of the Buddha. It is considered to be the first dagaba built in Sri Lanka following the introduction of Buddhism. This is considered the earliest 
monument
, the construction of which was chronicled Sri Lanka. The name Thuparamaya comes from "stupa" and "aramaya" which is a residential complex for monks.This chetiya was built in the shape of a heap of paddy. This dagaba was destroyed from time to time. During the reign of King Agbo II it was completely destroyed and the King restored it. What we have today is the construction of the dagaba, done in 1862 AD. As it is today, after several renovations, in the course of the centuries, the monument has a diameter of 59 ft (18 m), at the base. The dome is 11 feet 4 inches (3.45 m) in height from the ground, 164½ ft (50.1 m) in diameter. The compound is paved with granite and there are 2 rows of stone pillars round the dagaba. During the early period vatadage was built round the dagaba.
