This structure is the Polonnaruwa Vatadage. It’s a circular wall built around a small stupa which, it is said, held a relic of The Buddha. There are four entrances with ornately carved statues, ornately carved steps, and an ornately carved moon stone. The moon stone is at the base of the steps, is semi circular, shaped like a small throw rug. The entrances are situated at the four cardinal directions. At each of the entrances just beyond the circular wall is a statue of the Buddha. The four Buddha statues are (were) identical. Two are fairly intact while the other two are just remnants. Removing shoes was a requirement of entry.