The Kharbaqa dam has traditionally been attributed to the Romans, but more recent research has argued that it was constructed in the Umayyad period as part of the irrigation networks linked to Qasr al-Hayr al-Gharbi. The dam is around 345 metres wide and 20 metres high, but how long it remained useful is debated as the southern side of the dam is completely silted up and it is believed that this process happened relatively early in the life of the dam limiting its value to the local irrigation system.
Qasr al-Hayr al-Gharbi is the western of the two famous Umayyad palaces built to the east and west of Palmyra. This palace was built on the site of an earlier building and the stone tower still extant from that earlier phase has an inscription suggesting that it may have been part of a C6th monastery complex. The Qasr ("little castle") was built of mud brick, field stone and bricks and the whole was covered with a layer of stucco. The façade was covered with stucco decoration that was excavated from the site in the early C20th and reconstructed in Damascus as the façade of the National Museum. The frescoes and a number of stucco figurative three dimensional sculptures taken from the site are now on display in the National Museum.