The Jetavanaramaya (, "jētavanārāmaya") is a stupa, or Buddhist reliquary monument, located in the ruins of Jetavana monastery in the world heritage city of Anuradhapura, Sri Lanka. At 122 metres (400 ft) it was the world's tallest stupa and the third tallest structure in the world when it was built by King Mahasena of Anuradhapura (273–301). He initiated the construction of the stupa following the destruction of the Mahavihara. His son Maghavanna I completed the construction of the stupa. A part of a sash or belt tied by the Buddha is believed to be the relic that is enshrined here.