Abstract
Qala Kohzad was built on the heights of Weyzenhar/Veyzenyar Mountain in the southwest of Roumeshgan plain (western Lorestan). The archeological excavation of the site in the late 1960s revealed a series of architectural units made of stone rubble and plaster mortar measuring 17x38m. These spaces consist of two domed chahar-taq rooms with a cruciform plan, a quadrangular hall with corridors on its northern and southern sides, and some other facilities. The use of features such as decorative columns, plasterwork with a rose pattern, some interventions in architectural elements and bronze sculptures of unknown origin, led the explorer of the area to believe that the building of the Qala-Kohzad could be categorized as among the “mithraeums left from the beginning of Parthian rule.” However, the structural characteristics and the arrangement of architectural spaces, along with other evidence obtained from the building (namely, ceramics), do not confirm this assessment. In the current research, by combining the information obtained from the field survey and library sources, an attempt is made to shed light on the uncertainties about the function and chronology of the building as much as possible. Research findings and existing archaeological evidence show that the monument of Qala-Kohzad is not particularly related to a Mithraeum or an Anahita Temple. In fact, the remains of architecture or symbols and signs that can be used to prove the worship of the god Mithra or Anahita in Qala-Kohzad have not been found. The technical characteristics of the building, such as the use of curved arches and the use of conical philiposhes for erecting domes, along with the typology of the pottery samples, indicate that building belongs to the Sassanid period. The monument’s plan and the arrangement of architectural units, such as the combination of domed cruciform chambers with circular corridors and central hall, evokes the common pattern of fire temples of the Sassanid period. The existence of the remains of the base of the fireplace and the cubic-rectangular platforms in the interior of the chahar-taq of Qala Kohzad can be understood in the direction of performing religious ceremonies in connection with Zoroastrianism.
Keywords: Roumeshgan, Qala Kohzad, Mehrabeh, Fire Temple, Parthian and Sassanid Periods.
 
1. Introduction
The Qala Kohzad complex, located on the top of Veyzenhar mount at the westernmost edge of the Rumeshgan Plain, is one of the most significant architectural remains in Rumeshkan County and Lorestan Province. Archaeological excavations in 1988 uncovered an interconnected architectural complex consisting of two chahar-taqs surrounded by rooms, a central hall, corridors, and a columned vestibule, all built with rubble stone and gypsum mortar (Motamedi, 1992). Despite extensive excavations that revealed a substantial portion of the site’s architectural structures and a large number of cultural artifacts, these valuable findings have not been utilized to analyze the function and chronology of this important structure. Researchers such as Motamedi (Motamedi, 1992: 10) and Hassanpour (Hassanpour, 2010: 98) have proposed that Qala Kohzad was originally a mithraeum from the early Parthian period, later converted into a fire temple during the Sasanian era with minor architectural modifications. However, a more detailed assessment of the site’s architectural evidence and archaeological finds does not support this hypothesis. Therefore, this study aims to review all available evidence to complement previous studies and address the historical and functional significance of this important structure. The primary research question is: What was the function of the Qala Kohzad, and in what period was it constructed? The research hypothesis suggests that the architectural structure and spatial organization of Qala Kohzad do not align with Mithraic religious sites but rather correspond to the architectural characteristics of Sasanian fire temples. This study adopts a historical-analytical approach, gathering data through field visits and documentary research.
 
2. Data
The overall architectural composition of the site consists of a series of interconnected spaces extending along an east-west axis, measuring 38 meters in length and 17 meters in width (Fig. 2 & 3). The complex comprises two interconnected chahar-taqs (situated at the center and west), a rectangular hall, and several roofed spaces along the northern and southern sides of the hall. The entrance is located on the eastern side and was accessed via a staircase leading to the hall. The structures are built from rubble stone and gypsum mortar. The western/external chahar-taq of Kohzad is a cruciform space measuring 8.20×7.20 meters with two entrances on its northern and southern sides. Its core consists of four massive piers, measuring 1.2×4.2 meters (western piers) and 1.6×4.2 meters (eastern piers), supporting a dome - now-ruined. Interior elements of this structure include two flooring layers, a gypsum column base shaped like a truncated pyramid with grooves, a rectangular stone and gypsum platform adorned with star motifs, concentric circles, and floral patterns on its exterior surface. The central chahartaq features a cruciform plan with dual northern and southern entrances, a western platform, and a tiered central platform showing evidence of repeated fire use. To the east of the central chahar-taq lies a rectangular hall extending from east to west, flanked on the north and south by two vaulted corridors measuring 2×13 meters. A narrow partition divides the southern corridor into eastern and western sections, each with access points leading to the hall and the southern chamber of the central chahar-taq. Similarly, the northern corridor is divided into two sections by a narrow wall in its central portion.
 
3. Discussion
According to Motamedi, “Qala Kohzad was initially built as a Mithraeum for the worship of Mithra and possibly Anahita. During the Sasanian period, it was slightly modified to function as a fire temple. He attributes the central chahar-taq to Mithraic worship and the external/western chahar-taq to Anahita” (Motamedi, 1992: 10). His conclusion is based on cultural artifacts, including bronze figurines and decorative gypsum elements. However, to the best of our knowledge, no structure in Iran has been definitively identified as a mithraeum. The few possible examples, such as cave-like structures and architectural elements at sites like Zahhak Castle (Hashtrud), Mehr Gosaedi, and Mohammadabad Dashtestan, generally consist of corridors, multiple chambers, and main and subsidiary halls arranged in a linear fashion. A comparison of these sites with Qala Kohzad highlights more differences than similarities. Furthermore, the decorative elements found in Kohzad’s chahar-taqs (such as fluted grooves and floral motifs) do not appear in any known Mithraic sites. The chahar-taq structures and surrounding corridors in Qala Kohzad strongly suggest a religious function consistent with Sasanian fire temples. The site shares significant architectural similarities with other Sasanian fire temples such as Chen-Jiyeh (Vanden Berghe, 1977: 182), Kalak-Tamarkhow (Yousefvand & Miri, 2019), Palang Gerd (Khosravi et al., 2018: 283), Shiyan (Rezvani, 2006), and Mil-Milagah (Moradi, 2009: 179). Additionally, the presence of rectangular platforms and fire altar bases inside both chahar-taqs further supports this interpretation. The typology of the site’s architecture, including the chahar-taq design, spatial arrangement, vaulting techniques, and associated pottery, all point to a Sasanian-period construction.
 
4. Conclusion
The Qala Kohzad, located on Mount Veyzenhar southwest of the Rumeshgan Plain, consists of a large architectural complex featuring two domed chahar-taqs, a rectangular hall, surrounding corridors, a main entrance, a vestibule, and multiple rooms, all built using rubble stone and gypsum mortar. No substantial proof of Mithraic or Anahita worship has been found at the site. Instead, the architectural layout-including domed cruciform chahar-taqs, a central hall, and circumambulatory corridors- closely resembles Sasanian fire temples. Structural elements, such as fire altar bases and rectangular platforms, further confirm the site’s religious function within the Zoroastrian tradition. The construction techniques, including the use of rubble stone set in semi-milled gypsum mortar, massive piers, barrel vaults, and concave squinches, along with pottery typology, all indicate a Sasanian origin. Given the architectural consistency of Qaleh Kohzad with other Sasanian fire temples, it is concluded that Qala Kohzad was initially built as a fire temple during the Sasanian period.