The Ruwanweli Maha Seya, also known as the Maha Thupa (lit. 'the Great Thupa'), is a stupa (a hemispherical structure containing relics) in Anuradhapura, Sri Lanka. Two quarts or one Dona of the Buddha's relics are enshrined in the stupa, making it the largest collection of his relics anywhere. It was built by Sinhalese King Dutugemunu in c. 140 B.C., who became king of Sri Lanka after a war in which the Chola King Elāra (Ellalan) was defeated. It is also known as Swarnamali Seya, Svaṇṇamāli Mahaceti (in Pali) and Rathnamali Seya.
This is one of the "Solosmasthana" (the 16 places of veneration) and the "Atamasthana" (the 8 places of veneration). The stupa is one of the world's tallest ancient monuments, standing at 103 m (338 ft) and with a circumference of 290 m (951 ft).The original stupa had been about 55 m (180 ft) in height and was renovated by many kings. The Kaunghmudaw Pagoda in Sagaing, Myanmar is modelled after this stupa The Mahavamsa contains a detailed account on the construction and the opening ceremony of the stupa.