Hands of one of the four Buddha sculptures on the upper platform of the Polonnaruwa Vatadage in the ancient city of Polonnaruwa, Sri Lanka. The circular vatadage is an ancient structure unique to Sri Lanka. The building, which at one time had a roof, sheltered a stupa (dagoba in Sinhalese), a small dome-shaped structure built to hold relics of Buddha or a Buddhist saint. Buddhism played an important role in the culture of Polonnaruwa. Polonnaruwa, a UNESCO World Heritage site, was established as the capital city of Sri Lanka in the 11th Century, C.E., replacing Anuradhapura, which was plundered by invading armies from southern India. Many magnificent ruins remain in the royal city—parks, gardens, monumental buildings and temples, and a lake (tank) which supplied for an large irrigation system that still supplies water for paddy cultivation during the dry season.