Unknown to many, this moonstone lies at the entrance of a ruined building just behind the Ratnaprasada in Anuradhapura. This site is seems to be rarely visited without even a visible footpath. The most popular moonstone among the pilgrims and tourists lies on the building called Biso Maligaya. According to a plaque installed by the Department of Archeology, This moonstone is the most exquisite artistic creation of a moonstone found in Sri Lanka according to Prof. Senarath Paranawithana.
- Ancient Irrigation