Fardaghan, a New Sasanian Čahārṭāq in Markazi Province

Abstract
The location of Fardaghan historical village is in the northwest of Farahan Ccounty, in Markazi province. In this village, there are architectural remains of a castle and a four- Arches dome. Some texts have discussed some historical events related to this monument. In these sources, the castle and fire temple of Fardaghan, the transfer of the golden door of the fire temple to the Kaaba during the time of Hajjaj Ibn Yusuf, and its capture and destruction by the commander of Qom in 288 A.H. are mentioned. This research is based on the study of historical texts and archaeological excavation in the form of one season of trenching and one season of excavation. In this research, by examining and studying historical texts and architectural remains in the context of archaeological data, we attempted to determine whether the remains of the building obtained from the excavations of Fardaghan are the same fire temple of the Sassanid era that is mentioned in historical sources or not? During the field research conducted by the author, in addition to determining the area and proposing the boundaries of the square dome building and the castle, the main building (four-Arches dome) has also been pursued and explored. The architectural data indicates the existence of a square four-roomed building with a side of 17 meters with four Turkish brick columns, of which two columns of the southern half have been obtained so far. The resulting quadrangle has a circular corridor with stone walls 1.5 meters thick, which is plastered from the inside. The building has one entrance in the center of the east and west sides and three entrances in the south side. The wall on the north side of the building is currently buried under the clay texture from the Qajar period. A comparative study of historical texts and field research shows that this building is the same fire temple that is mentioned in these sources. Following the above research, a complete excavation and the identification of the general structure of the building, as well as more archaeological data, will determine the additional typological studies of this building with the other four-arch domes of the Sassanid period.
Keywords: Sasanian Period, Fardaghan, Castle, Square Dome, Fire Temple.
Introduction
The Farahan Intermountain Plain, situated in the heart of Markazi Province, lies on the western border of Iranian Central Plateau and the eastern border of Central Zagros. Throughout the Sasanian era, certain locations in the Farahan area held immense religious and political significance. This was primarily due to the presence of notable structures such as the Fardaghan Fire Temple, which remained illuminated until the 3rd century AH before being demolished by the Qom ruler.
The modern Markazi Province is an integral part of the historical land of Iraq-i Ājam. This region, along with Fars and Kerman, was a key area for the four-arches domes (Čahārṭāq) during the Sasanian period (Mohamadifar & Amini 2015: 126). The Ateshkoh Fire Temple near Nimur Mahalat and the historical village of Fardaghan are examples of these domes. Therefore, the Fardaghan Fire Temple will be noted in Iranian archaeological literature.
Several historical texts have explored various events linked to this monument. These sources mention the castle and fire temple of Fardaghan, the relocation of the golden door of the fire temple to the Ka’aba during Hajjaj Ibn Yusuf’s time, and its capture and destruction by the Qom ruler in 288 AH. This investigation draws upon historical texts and archaeological excavation, encompassing one season of test trenching and one season of systematic excavation. Through the examination of historical texts, architectural remnants, and archaeological evidence, our aim was to determine whether the building remnants discovered at Fardaghan correspond to the Sasanian-era fire temple mentioned in historical records. 
Discussion
Fardaghan Village, situated 50 kilometers northwest of Farmahin Town in Farahan County, is a historical village surrounded by towering mountains in a rugged valley. Prior to the author’s field research in Fardaghan, remnants of the historical Fardaghan Castle and what was believed to be the fire temple of Fardaghan were discovered. Additionally, a column made of brick was found in the courtyard of a residential building inside the village.
Through meticulous investigation and excavation, the findings have unveiled the remnants of a castle occupying an expansive one-hectare expanse. While the walls on the western and northern sides of the castle have managed to withstand the test of time, other sections have endured damage and alterations. Nestled within the castle’s central region lies the remains of a building known as the fire temple. Further exploration within the primary structure has led to the unearthing of a symmetrical four-arched construction, boasting a side length of 17 meters. This structure encompasses a circular corridor, featuring walls measuring 1.5 meters in thickness. The corridor’s walls reach a maximum height of 2.5 meters and are predominantly constructed using stone, which has been plastered on the interior.
When examining the typology of four-arches domes in Iran, it becomes evident that the Fardaghan’s building bears resemblance to the second type of Sasanian four-arches dome (Čahārṭāq) as categorized by Dietrich Hoff in Fars (Hoff, 2013: 128). Like this specific group of Čahārṭāqs, the Fardaghan building incorporates a corridor encircling its central dome. Based on a comparative analysis of historical texts and field research, it can be concluded that this particular building is indeed the fire temple referred to in those sources. The research provides a solid foundation for conducting a comprehensive excavation, which will enable the identification of the overall structure of the building. Furthermore, the acquisition of more archaeological data will facilitate further typological studies on this building, particularly in relation to the other four-arches domes from the Sasanian Period.
Conclusion
The historical records are in line with the architectural information of the main structure, particularly its shape and layout, indicating that the four-arched building in Fardaghan is likely the fire temple referenced in historical texts. Despite the discovery of a unique column here which does not parallel other Sasanian Čahārṭāqs, other architectural features like corridors, four-arched designs, solidity, and grandeur provide further evidence of its association with the Sasanian era. The architectural evidence obtained suggests a resemblance to a building mentioned in Qom’s history during the third century AH, which was destroyed during that period. These factors solidify the connection of the discovered structure to the fire temple of the Sasanian Period. Based on Hoff’s classification of four-arches domes (Čahārṭāq) from the Sasanian Period, the building unearthed in Fardaghan falls under the second type. In fact, the square-shaped dome of the Fardaghan four-arches building is supported by four sturdy brick columns and is surrounded by a corridor. When comparing the building plan of Fardaghan with other four-arches domes in Iran, such as The fire temple of Ateshkoh in Mahalat, Bazeh Hour Čahārṭāq, Shian, Siahkal, and Julian, it becomes evident that the Sasanian four-arches buildings share important characteristics with Fardaghan, particularly the presence of four columns and a circumambulation corridor. The suitable geographical location of Fardaghan Village played a significant role in the establishment of a fire temple in this area. Furthermore, the distance of Fardaghan from the main centers of power during the Islamic Period contributed to the longevity of the building, which lasted until the third century AH.