Qasr al-Hayr al-Sharqi (Eastern al-Hayr Palace or the "Eastern Castle") is a castle (qasr) in the middle of the Syrian Desert. It was built by the Umayyad caliph Hisham ibn Abd al-Malik in 728-29 CE in an area rich in desertfauna. It was apparently used as a military and hunting outpost. The palace is the counterpart of Qasr al-Hayr al-Gharbi, a nearby castle palace built one year earlier.
Qasr al-Hayr al-Sharq is 27 kilometres (17 mi) from Al-Sukhnah and 100 kilometres (62 mi) from Sergiopolis (Rusafa), near Bishri Mountain near Palmyran Middle Mountains.
Like other Umayyad architectural works, the construction style was influenced by Byzantine and Sasanian architectures.
Evidence of a complex water infrastructure system suggests that the site was comprehensive in scope. The remnants of this Umayyad city are encompassed by a large outer enclosure measuring some 7 sq km., probably reserved for gardens, animal husbandry, and other agricultural purposes. Within it the site includes two enclosures, one significantly larger than the other, and a bathhouse.
This site was added to the UNESCO World Heritage Tentative List on June 8, 1999 in the Cultural category.
During Syria Civil War, Qasr al-Hayr al-Sharqi was captured by armed groups in 2013, then by ISIS. The Castle have been damaged by looting and vandalism. The visitor house has been burgled. The Syrian Government Army recaptured the castle on 22 August 2017. ISIS recaptured the castle again on 30 September 2017.