Shahr-i Gholghola

This city was built for the first time perhaps in the Achaemenid period, The three-storied Citadel Palace is perhaps the only known monumental Saffarid building extant. It is unusual in its design with a serpentine outer wall of baked brick, non-squared corners, and a location at the eastern edge of the Citadel rather than the center. The Saffarid buildings were reused in the Ghaznavid and Ghurid periods and some changes were made in them, including the addition of a bathhouse on the Citadel and an expansive Lower Palace in the enclosure beneath, until they were destroyed by Genghis Khan's army in 1222. The date of the conquest is confirmed by a set of coin hoards sequestered along the bazaar uncovered by the archaeologists from that date. During the period of Timur Lang, this area witnessed wars and was destroyed, but the successors of Timur also built or restored some buildings. The remains of this period were very few and mainly included mansion houses and canals built inside the outer defensive walls, which had gone out of use. ==Key buildings and areas of the site==

The structure of the city is such that a standing walls over 1 km in length and over 10 m high on each side. Also, there were three moats and five different wall systems to further protect the city and the main palace of the citadel at the center of the site. In their several years of research in this place, the mentioned team found that the clay decorative elements used in the architecture lacked the elaborate designs of the constructions of Mahmud Ghaznavi and his successors in the 11th and 12th centuries AD. And according to the team, this indicates that the palace was built slightly earlier than that, making it the only known example of 10th-century Saffarid architecture. Lower Palace Mosque and Bazaar In this place, a historical mosque was discovered in 1972 by The Helmand Sistan Project team, which has been built during the Saffarid period. Per The Helmand Sistan Project team statement, this mosque has a qibla wall and mihrab on the west side, a porch on the east and a central courtyard built with baked bricks. The southern entrance of the mosque a commercial street that contained a bazaar area and has been rebuilt several times in different periods. A caravanserai was found across the street from the mosque. This mosque was also destroyed during the attack of Genghis Khan's soldiers. Circular Enclosure Outer Enclosure ==Irrigation system==

The Shahr-i Gholghola was irrigated by the Zarkan and Zorkan canals, which were separated from Helmand River and went towards Chekhansur and Kang. During the Islamic period, most diversion and storage dams were built in Sistan and Hirmand valley, which shows the skill and ability of Sistanis in water management. Mirabi system has also been very strong in Sistan. Bandabafan and Mir Aban Sistani were experts in knowing the longitudinal slope of the streams Sistan was attacked several times by its enemies and all its irrigation systems were destroyed. One of the most violent of them was the invasion of the Mongols in 620 A.H. and the last blow was given by Timur Lang to the body of Sistan, who in 785 A.H. besieged the city of Zaranj with his vast army and later destroyed it completely. Timur destroyed the entire irrigation system and turned the most prosperous land, which was called the granary of the region, into ruins. Ghurids (Sultan Aladdin), Mongols and Timurids (Timur Lang and later Shah Rukh Mirza) played a major role in destroying the irrigation system of Sistan, and Sistan never returned to its former glory and prosperity. ==See also==