Dimbulagala, once called ‘Gunner’s Quoin’ by the British, is the most prominent ridge in the plains of the lower reaches of the Mahaweli Ganga. The isolated mountain range located 15 km southeast of Polonnaruwa measures about 5 km (3 miles) in length and 2.5 km in width. With an altitude of 543 m, Dimbulagala is the highest peak in Polonnaruwa District.
Situated on the opposite side of Sri Lanka’s largest river and therefore historically belonging to the principalities of the island’s southeastern lowlands (Rohana) and not to the realm of the Anuradhapura kings (Rajarata), the quite remote Dimbulagala ridge was an abode of reclusive forest-dwelling monks during the entire Anuradhapura period. An architecturally more prestigious monastic complex of the Pabbata Vihara type was built in the late Anuradhapura period, indicating that Dimbulagala had become a focal point of a local section of educated village monks, too. In the Polonnaruwa period, however, Dimbulagala was a monastic center of utmost importance for the history of Theravada Buddhism. Actually, in the 12th and 13th century it was the most important monastery outside the capital, of significance even for Buddhist Orders of Southeast Asian nations.