Sandakada pahana, also known as Moonstone, is a unique feature of the Sinhalese architecture of ancient Sri Lanka. It is a carved semi-circular stone slab, usually placed at the bottom of staircases and entrances. First seen in the latter stage of the Anuradhapura period, the sandakada pahana evolved through the Polonnaruwa, Gampola and Kandy periods. According to historians, the sandakada pahana symbolises the cycle of Sans?ra in Buddhism.The ancient chronicle Mahavamsa and Pali literature such as the Samantapasadika refer to the sandakada pahana as patika. Sri Lanka.