ShapurKhast Castle, Dež-e Shāpūr-Khwāst, Falak-ol-Aflak Castle, known in ancient times as Dezbaz as well as Shapur-Khast, is one of the most impressive castles in Iran. It is situated on the top of a large hill with the same name within the city of Khorramabad, the regional capital of Lorestan province. The Khorramabad River runs past the eastern and south-western side of the ShapurKhast hill providing the fortress with an element of natural protection. Today, the western and northern sides of the hill are bordered by the residential districts of Khorramabad.