The Jetavanaramaya is a stupa, or Buddhist reliquary monument, located in the ruins of Jetavana monastery in the UNESCO world heritage city of Anuradhapura,[2] Sri Lanka. At 122 metres (400 ft), it was the world's tallest stupa,[3] and the third tallest structure in the world[4] when it was built by King Mahasena of Anuradhapura (273–301)