A comparative Study and Comparison of the Čahārṭāq of Khorramdasht Kashan with Sassanian Religious Monuments

Abstract
Undoubtedly, in religious archaeological studies of the Sassanid era, fire temples and chahartaqis are very important. In the doctrines of the Zoroastrian religion, fire was one of the sacred and respected elements of the Zoroastrian community, and with the legitimation of the Zoroastrian faith, fire temples/chahartaqis emerged as a prominent setting for rituals and religious customs in Sassanid society. One of the most critical fire temples of the Sassanid period in the Kashan cultural zone is the Chahartaqi of Khorram Dasht, which is not well known despite the fame of other chahartaqis in this area, such as the Chahartaqi of Niaser and the fire temple of Vigol. The Chahartaqi of Khorram Dasht is located in the southeast of Kashan near the village of the same name, in the low-lying moorlands. Based on the evidence, it seems that the Chahartaqi of Khorram Dasht is a type of composite building, and traces of architectural remains can still be seen today around that (north of the area). The present research, conducted through a combination of fundamental research employing a descriptive-analytical approach, together with field investigations and library-based studies, seeks to answer the following questions: “Based on the architectural evidence preserved within this structure, can it be demonstrated that the building functioned as a fire temple?”, “What architectural model did the plan of Khorram Dasht Chahartaqi follow?”, and finally, “According to Zoroastrian religious texts, what type of fire was maintained in this fire temple?” Based on the results, the analysis and comparison of the architectural characteristics of the Khorram Dasht fire temple with other contemporary Sassanid examples reveal substantial similarities between this monument and its counterparts in several respects, particularly in terms of its architectural plan, indicating that it was constructed according to an almost identical pattern. Furthermore, the examination of adjacent architectural remains, such as circumambulatory corridors, supports the interpretation of the structure as a fire temple. Considering the classification of sacred fires during this period and the fact that Atash-i Bahram (Bahram’s Fire) was maintained exclusively in the principal and permanent fire temples (namely the three great fire temples), it is most likely that the fire maintained at this site was of the local Atash-i Adoran type and was kindled during specific occasions and ceremonies.
Keywords: Sassanian Period, Fire Temple/ Chahar Taq, Khorramdasht, Kashan city.


Introduction
In the Sassanid era, the central government’s attention to religious unity led to the promotion of the construction of religious structures associated with what is today known as Zoroastrianism in different parts of Iran. Accordingly, the study and examination of the religious monuments of this period play a significant role in the enhanced recognition and understanding of historical, artistic, and architectural issues of the Sassanid period. During the Sassanid period, in addition to the construction of essential and prominent fire temples such as the Azargoshasb fire temple in Takht-i Soleyman or the Azar-Barzin Mehr fire temple in Khorasan and Azar Faranbagh in Fars, many chahartaqis (chahartaqi structures) were built in which religious ceremonies were held; this reflects the importance of the construction of fire temples and public buildings. Unfortunately, so far, there are only a small number of Sassanid fire temples from the middle and late Sassanid periods that have been identified through archaeological excavations, such as Kuh-i Khwaja, Takht-i Soleyman, Bandian, Shiyan, Khoune-ye Div, Palang Gerd, Dover Castle, Mil-e Milegeh, the Vigol fire temple, and, outside the political borders of Iran, the Meleh Hairam fire temple in Turkmenistan; this dispersion can be seen as a reflection of the expansion of the Zoroastrian religion. In addition to the mentioned cases, several examples of this category of structures have also been identified in Isfahan Province, one of which is the chahartaqi of “Khorram Dasht,” located in the southeast of Kashan, as an evidence of Sassanid religious architecture in this part of the Iranian Central Plateau. In the following section, we aim to address the questions raised in this study through comparative analysis and interpretation.
The purpose of the current research is to introduce the chahartaqi of Khorram Dasht (including its architectural elements, materials, and spatial organization) and compare the existing archaeological and architectural evidence of this building with other fire temples of the Sassanid era. The introduction and analysis of this chahartaqi, in addition to introducing a fire temple from the Sassanid period, will be a step towards a better understanding and explanation of the status and role of the Kashan region within the Sassanid territorial sphere. The research questions are: “Based on the evidence preserved in the architecture of this building, can it be proved that it was used as a fire temple?”, “What model did the architectural plan of Khorram Dasht fire temple follow?”, and finally, “According to Zoroastrian religious texts, what kind of fire was lit in this fire temple?”
 
Discussion
The Chartaqi of Khorram Dasht is located in Isfahan Province, Kashan County, 20 km southeast of the city center, northeast of the village of Khorram Dasht. The building stands on a stone platform (soffe) situated on a moorland to the east of the village and is aligned with cardinal directions. The stone platform (soffe), in addition to providing a foundation for the Chartaqi, extends approximately 2.5 m on all four sides and probably covers the circular ambulatory corridor of the building (Fig. 3). Of the Chartaqi building, only its four main pillars have survived, while the arches have been reconstructed. Unfortunately, no information is available concerning the construction method of the dome due to its destruction; however, it can be assumed that it originally possessed a high oval dome, by comparison with the surviving domes of other contemporary structures. The thick pillars of the Chartaqi measure approximately 290 cm in width and 450 cm in length, and rest on a square stone platform approximately 4 m on each side; on the interior of the building, each pillar is considerably wider, thereby creating a bench-like surface near floor level. Between the base pillars, portals open in the four cardinal directions, which connect to the Tawaf corridor behind the pillars, as is typical of many four-arched Chartaqis of this period. The width of these corridors is approximately 155 cm, and large stones are used in the core of the walls. The wall is visible on the east, west, and north sides of these corridors. The central space of the Khorram Dasht fire temple is square. Inside this central space, precisely in the middle of the building, beneath the now-vanished dome, a circular structure 100 cm in diameter can be seen, which most likely represents the remains of the base of the fire altar or the stone bench of the fire altar (Fig. 7), since a centrally placed fire altar was one of the essential elements of Sasanian fire temples. Furthermore, in the northern part and at a distance of about 4 m from the Chartaqi, there is a stone structure, which comprises a sizeable quadrangular space aligned with the pillars of the Chartaqi in a north–south direction and incorporates side rooms; traces of plaster coating on the walls and the windows of the rooms have survived to the present day (Fig. 10). The walls of these rooms are approximately 5 m in length, and the surviving portions stand about 110 cm in height.
 
Conclusion
Analysis and comparison of the architectural style of the Chartaqi of Khorram Dasht with other contemporary Sassanid samples discussed in the preceding sections reveal similarities in several respects, including the building plan and materials employed in its construction. The layout comprises a central square space with four portals on each side and a peripheral corridor comparable to known religious buildings of the Sasanian period. In Dietrich Huff’s classification of fire temples and Chartaqis, this complex can be placed within the second group of Sasanian Chartaqis, since a Tawaf corridor is observable around it, and the building can most likely be identified as a religious structure functioning as a fire temple of the Sassanid era. The materials used in many Sassanid Chartaqis and fire temples consist of stone rubble and gypsum mortar, as observed in the Chartaqi of Khorram Dasht in Kashan. Given the limited number of known fire temples that housed an Atash Bahram, it is probable that a lower-grade fire was maintained at this site. Consequently, in the Chartaqi of Khorram Dasht and fire temples of this type, which lack complex architecture, the Atash Adoran (local fire) was venerated, and the remains of the fire altar are located at the centre of the fire temple.