By selecting northwestern Iran as the early capital of Ilkhanid dynasty, Mongol rulers governed this area for about one century; this would have been the official route of administration and communication between Mongolia, Inner Mongolia, northeastern China, and Iran. Although the period of 1256-1335 is seen as the era of cultural interventions from Mongolia and Inner Mongolia into the northwestern Iran (Moradi and Omrani 2020), the architectural influences during Mongols' dominion has been less considered by the scholars. In this way, recent archaeological developments related to these regions have begun to shed new lights on recognizing spatial relations and the applications of Ilkhanid sites in northwestern Iran (Moradi and Omrani, 2019). In the outskirts of Maraghe lies the site of an underground structure known as the Mithraeum also the Imamzade Masum. This building has occupied archaeologists some of whom suggested that the architecture of this monument served as a Mithraeum and/or monasteries imported by the pre-Islamic dynasties in Iran (Shekari Niri, 2006). From an architectural point of view, this monument has three accessible areas: a main space surrounded by four domed chambers; a four-domed hall with a pillar in its center and a set of three long chambers some one hundred meters away. A parallelogram-shaped opening with a rough semi-circular roof and a single step of masonry blocks crosses into the central chamber. On the south of the main chamber is a large square-roofed alcove. The alcove leads to a little cavity that contains two niches. A second access to the largest domed room leads through an opening on the southern end of the east wall of the chamber via a passageway. The domed chamber has a remarkably well-preserved ceiling faceted in the Ilkhanid stylistic style. Each fact is a square or triangle and only one facet has any decoration left on it. It sounds that the calligraphic artwork of the rectangular hall was left incomplete and possibly brought to an abrupt halt (Azad, 2010). According to the gross fabric of the pillar hall which is made owing to a precipitate process of carving in compare with the other sections, it could be concluded that this part has been added during the recent renovations of this structure (Moradi and Omrani, 2019: 90). By highlighting the word "Butkhana" (i.e. a place of Buddha or idols) in the primary sources, other scholars believe that here could be marked as a Buddhism Temple (Azad, 2010). Varjavand's studies were among the prior investigations about these units. According to his conclusion and without any sufficient documentations, this underground complexes date back to a period belonging to the prehistoric settlements, reused as a Mithraeum during historic era and renovated as a religious complex with the application of mosque and convent during the Islamic ages (Varjavan 1972). It is argued that Mongol conquest of Iran indeed has an architectural legacy; it also sets the models of elite architecture of the steppe which were particularly relevant to the religious architecture, carried on during the early phases of Mongol triumphs. According to the results, the combination of a corridor leading to one or more chambers is not entirely random in the so-called Mihr Temple of Maraghe but also shares an exact assimilation of those in Mongolia, Inner Mongolia, and northeastern China (Moradi and Omrani, 2020). Using analytical expository study of the architectural evidences from Mongolia, Inner Mongolia and northeastern China, this paper is aimed to categorize the identity of similar structures in northwestern Iran as the same imported architectural heritage from these areas.
It is well documented that Mongols′ monarchy in the thirteen and fourteenth centuries fostered the direct exchange of ideas and practices between diverse cultures and religions. Scholars have evaluated the damage and the benefits brought by the Mongols to the Islamic world in military, religion, politics, economy, and culture fields (Bayani, 191: 87). It cannot be said that the Mongols, who lived in clans under hereditary leadership at the beginning of the twelfth century, were prepared for controlling the enormous territory that they had conquered. Nevertheless, the Mongols succeeded in creating a novel administrative system; they maintained some of the practices of the people of the steppes such as sharing out-of-subject people among the members of the imperial family, adding the elements of Chinese administrative practice. They also used the experience of Turco-Mongols who were integrated into the empire such as the Uighurs who ruled Mongolia and the Khitan who governed northern China (Lingley, 2014). The arrival of the Mongols in northwestern Iran in the 13th century transformed the Islamic provinces of northwestern Iran into a political, religious, and cultural region between Islam and Mongolian homeland traditions. The impact of this settlement of Turko-Mongols should be considered when discussing architectural motivation to create the so-called Mihrt Temple of Maraghe. Undoubtedly, the funeral architecture in accordance with early Mongolian customs was inevitable to cover funeral prospects of Mongol's elites and aristocratic families. Focusing our attention on the funeral architecture of Mongolian and Inner Mongolian traditions and comparing these underground architectures with Iranian specimens in "Maraghe", "Nir", and "Azar Shar" provinces in northwestern Iran, this short essay will try to categorize the so-called Mihr Temple of Maraghe as the same funeral units of Mongolia, Inner Mongolia, and northeastern China. According to the results and by comparing the architectural forms between Northwest Iran, Mongolia, Inner Mongolia and Northern China, not only there is no difference between plans and design, but also a same language of architecture has been repeated in both regions. According to the results, three type of tomb constructing method could be considered in an area including Inner Mongolia, Mongolia and Northeast China; one including a passageway end up with an antechamber and main chamber room which is mainly formed the structure of the tombs in Northeast China like tomb of Xu Xianxiu (Figure 9) and those in Bashon. Second is a corridor in connection with two successive domed chambers in Northeast most point of Inner Mongolia in Kogoryo's tombs which should be considered as the point where single chambers and multi chamber tombs overlapped; and the third: including a corridor, antechambers, main chamber and two bilateral rooms containing horse bones, warfare and ceramics. Although scholars cannot securely identify the origin of the design of Northwest Iran underground architecture, but from this point of view, Maraghe’s underground architecture might be a tomb in accordance with the architectural projects of Mongolian’s tomb like those in Huatehua, Abaoji's tomb, Shoroon Bumbagar tomb (Figure 10), tomb of Shoroon Dov barrow (Figure. 11), tomb of Xiao Yi, Tangut's royal tomb and tomb of Mme Yi; while Abazar’s tomb will follow the plan of tombs in Kogoryo and Azar Shahr’s tomb will be an exact copy of those in Northeast China. (Figure. 15) Since Mongol invasions of Iran (1256) is the most common reason of this transition before the time that Ghazan started a new architectural movement towards funeral architecture by establishing his complex known as Ghazaniyya (1320); Northwest Iran’s tomb most belong to the period between mid-13th to the early 14th centuries.