Thuparamaya: The Oldest Stupa of Sri Lanka – Have you ever wondered which the oldest Stupa in Sri Lanka is? Constructed in the reign of king Devamnampiyatissa, Thuparamaya is the first Stupa to be erected in 250BC-210BC in the watch of Mahinda who was an envoy sent to Sri Lanka by the Indian King Ashoka. It was Mahinda and Sangamiththa, son and daughter of King Ashoka, who brought Buddhism to Sri Lanka.