Abstract
Hamadan great mosque, the oldest mosque in the old urban context, is located between the city market and the central square. This prominent mosque belongs to the early Islamic centuries, which has been rebuilt during various periods, especially the Safavid and Qajar periods, but isn’t remains of the ancient structure of the mosque, and the current structure belongs to the Qajar period. Despite the general features of this work, the shape of the mosque building has a great impact on bringing the building in line with the climate. Now the question arises to what extent has the region’s climate been able to influence the process of mosque formation?  And to what extent does climate modeling ensure the durability of the mosque’s structure? Based on the above questions, the purpose of the present study is to introduce and analyze architecture of great mosque by using descriptive-analytical method and relying on study resources and field studies to provide answers to the questions raised. The result of such a study can be seen in influencing the architectural features of the mosque from the region’s climate; this work, in addition to its religious function, the location of the mosque and its location along the main market of the city, has led the mosque to play an important role. According to the architectural structure of the mosque, the major developments in the building are related to the Qajar and contemporary periods; the structure of the columns of the nave of the mosque, It has a dome, minaret and sangab, and is the only example of a dome mosque of historical value in the urban context of Hamadan.
Keyword: Hamedan, Great Mosque, Architecture, Climate.

Introduction
Hamadan great mosque has always been one of the most important historical, architectural and archeological studies in Hamadan. About change, development and restoration carried out in the Mosque of historical, geographical and social remained critical of the Islamic period. Which can sometimes be compared with evidence in the current structure of the mosque, and sometimes little archaeological evidence suggests that parts of the building existed in the past. As it comes from historical sources, the core of the structure of the Hamadan mosque dates back to the Early Islamic period, which has been repaired and added to over the course of the following centuries (Hojbari, 2006). In addition to the religious function, the location of the mosque and its location along the main market of the city have led the great to play an important role in shaping the design and layout of the city (Mehriar et al., 1999: 54). Due to the architectural structure of the mosque, the major developments in the building are related to the Qajar and contemporary periods. The structure of the mosque is subordinate to the pillar-shaped hall, has a dome, a goldsmith and a Sangab, and is the only example of a dome mosque in the urban context of Hamadan. Structural features and climatic principles governing the structure of the mosque led the author to fully describe the architectural structure of the mosque of Hamedan in a descriptive-analytical way.  Undoubtedly, this method of analysis can greatly eliminate the gaps in the study of structural, decorative, and climate change in the structure of the mosque. Based on the aforementioned approach and based on geographical, historical and architectural texts, a comprehensive and complete analysis of the mosque’s location and its architectural and structural analysis is obtained. Therefore, in this study raised the following questions: What extent the climate of the region has been able to influence the process of mosque formation? And to what extent does climate modeling ensure the durability of the mosque’s structure? 
 
Great Mosque
The square-rectangular square-plan mosque is incomplete, with a rectangular courtyard spanning three porches in the South, East and North, several bedrooms, a brick-covered dome, a dome, six minarets and several chambers.  The building under consideration from the perspective of construction and architecture from several different and interrelated parts such: Entrance, Vestibule, Courtyard, Ivan, Chambers, and the hall is formed around. The main entrance of the mosque has been West and market in the past, but with the creation of new buildings and a new entrance on the North side of “Ekbatan Street” the main entrance has been moved to this direction. The old mosque entrance to the market can be accessed through a vestibule to various parts of the mosque. Another entrance to the mosque is on the Southeast side of the market through a corridor. The courtyard of the mosque has a large pond in the middle, porches, chambers and halls around, the courtyard is about 2 meters below the adjacent alleys. The South porch of the courtyard has two shallow arches that have two short and thick minarets on top of this porch. Behind the porch is the dome space of the mosque, which, along with the porch, forms the core of the old mosque, with an altar built on the South side. The dome is of two-shell type and is of architectural suitability; the dome leads to the columned bed sheets through the side porches; on the West side of the dome is a mosque with proportional stone columns that access the courtyard and dome through the entrances. On the West side of the courtyard and adjacent to the aforementioned nightclub is another columned hall, opposite the South porch and on the other side of the porch aisle and bed sheets in a new way with flat cover built on top of the middle porch of the two minarets, which is an extension of the recent period, the porch overlooking the new mosque on Ekbatan Street also has two minarets (Molazadeh and Mohammadi, 2000: 243-244).  

Conclusion
Designers of Hamedan great Mosque have applied techniques to adapt to the climatic conditions of the cold foothills, a major problem in these areas is winter cold. Therefore preventing heat dissipation in different parts of the building is a top priority for designers (Tahebaz and Jalilian, 2011: 63). The plan of the mosque is a square-rectangular mosque that is integrated with the surrounding area and the mosque building is adjacent to the adjacent buildings, which also helps maintain the heat inside the mosque as well as the adjacent buildings (Pourshabanian, 1397: 67). The mosque has a central courtyard with a low infrastructure compared to the entire mosque. Part of the body of the mosque is submerged in the ground due to the lower level of its adjacent street texture, leading to greater vulnerability of various parts of the building to moisture(Ibid: 47-48). And besides the beauty of the building materials, it is also damaged (Ibrahimzadeh, 2015, 2: 796).  

Abstract
The native and traditional architecture of each region has been derived from the climate and geography of that region, and mosques as the most important permanent building of Islam in different cities and climates have developed and survived over time by maintaining their unique characteristics in accordance with the climate of each region. The survival of the structure of the historical mosques of Hamedan has also been influenced by the climatic indicators of the region and the climate has guaranteed the structure of the mosques for many years and has provided the possibility of peaceful coexistence of architecture with the environment and its integration. On this basis, this question can be asked that to what extent did climatic characteristics influence the process of forming mosques? In other words, to what extent have climatic factors been effective in creating similar shapes and forms in the building of Hamedan mosques? Its purpose is to recognize Hamedan’s climatic indicators in the structure of mosques by relying on study sources and field surveys to provide a basis for answering the mentioned questions .Considering that the quality of the structural model and the materials used in the mosques of Hamadan city have many similarities with each other due to the high foothill climate of the region ,and the design matching the climate in most of the mosques of this region is similar to other cities of the high foothill climate and mountainous has been observed, as a result, by studying and comparing architecture and climate, the degree of adherence to climate in the architecture of these valuable structures can be obtained. In order to understand the architecture of the historical mosques of Hamadan city, all the documentary, library and field data have been reviewed in a comprehensive way to reveal the effects of climate on the architectural structure of the mosques.
Keywords: Mountainous Region, Hamedan, Architecture, Mosques.

Introduction
In most of the historical and geographical sources of the Islamic era, the life and position of the city and its landmark works such as mosques, especially the Grand Mosque, have been talked about, and it has always had many study attractions for archeology, history and art researchers. In terms of urban identity, Jame Mosque of Hamadan has an old structure from the early Islamic era. However, the majority of neighborhood mosques were built in the neighborhoods of the city after the Safavid period, and a number of mosques, which are related to the Islamic Middle Ages, were revived during this era and the Qajar era. The plan of these mosques is square-rectangular and they follow the pillared nave pattern, without minarets and garlands. The majority of these mosques are built along the bazaar or on the side of the main roads of the city and play an important role in the formation of the design systems and public image of the city. Despite such a key position in the context of the city, investigation and research on the structure of mosques has often been scattered and focused only on the expression of architectural features. Therefore, the role of some influential factors such as climatic indicators in the structure of mosques, which are adapted to the climate of each region as much as possible, has been less noticed. Based on the main objectives of the article, the author aims to examine the architectural structure of the mosques of Hamedan city based on the climate of the region in the time frame of the Islamic era .Based on the mentioned approach, the review of historical and contemporary written sources, archeological data, excavation documents, and field surveys can provide researchers with a comprehensive and complete analysis of the exact location of mosques in the urban context and their architectural analysis based on the region’s climate.

Introduction
The mosques of Hamedan city, as one of the prestigious cities of many centuries of Islam, are very important in the civilization of the Islamic era from various aspects of study and research. In most of the historical and geographical sources of the Islamic era, the life and position of the city and its landmark works such as mosques, especially the Grand Mosque, have been talked about, and it has always had many study attractions for archeology, history and art researchers. In terms of urban identity, Jame Mosque of Hamadan has an old structure from the early Islamic era, which has been repaired and restored in different periods and additions have been added to it. Investigations and evidence show that the majority of neighborhood mosques were built in the neighborhoods of the city after the Safavid period, and a number of mosques, which are related to the Islamic Middle Ages, were revived during this period and the Qajar era. There is a mosque in each neighborhood of Hamadan city, among these mosques, we can mention Nazarbeg, Shalbafan, Chaman-Chopanha, Prophet, Imamzadeh Yahya, Gazran, Mirzataqi, Kalpa, Kebabian, Haji, Haj Kalbali and Alavian mosques. The plan of these mosques is square-rectangular and they follow the columned nave pattern, without minarets and garlands. Considering the importance of a significant number of mosques that are scattered in the city of Hamadan, each one is located on the path of one of the main neighborhoods of the city in the old context. The majority of these mosques are built along the bazaar or on the side of the main roads of the city and play an important role in the formation of the design systems and public image of the city. Despite such a key position in the context of the city, the investigation and research about the structure of mosques has often been scattered and focused only on the expression of architectural features. Therefore, the role of some influential factors such as climatic indicators in the structure of mosques, which are adapted to the climate of each region as much as possible, has been less noticed. Based on the main objectives of the article, the author aims to examine the architectural structure of the mosques of Hamedan city based on the climate of the region in the time frame of the Islamic era. Undoubtedly, this method of investigation and analysis can solve the study gaps regarding the architectural structures of mosques and climatic effects in them to a great extent. Based on the mentioned approach, the review of historical and contemporary written sources, archeological data, excavation documents, and field investigations can provide a comprehensive and complete analysis of the exact location of mosques in the urban context and the architectural analysis of mosques in Hamadan city. To provide researchers with the climate of the region.

Discussion
Although the historical mosques of Hamedan follow the general principles of mosque building, they have used methods to adapt to the cold climate of the region. The presence of courtyards in Hamedan mosques is often shown in three ways. Due to the unevenness of the city fabric in all areas, in sloping lands, part of the body of mosques is sunk into the ground. In addition to the external structure of mosques, often the internal parts are also designed under the influence of climatic conditions. Often, the roof of the mosques in this area is not dome or flat due to weather conditions and the amount of snow and rain. Comprehensive mosques are excluded from the general rule due to their centrality in the urban context of each region and often have a dome cover. Except for comprehensive mosques, keeping the balance in the ambient temperature as one of the design priorities has led the majority of mosques in this region to have flat or smooth roofs.
In some mosques of this region, there is only one nave with the characteristics of winter naves, and in other mosques, due to the more appropriate use of the nave space in different seasons, dual spaces have been considered for winter naves and summer naves. The axis of placement of the winter and summer Shabestan in the design of the mosque depends on the climatic pattern of the region. The number and dimensions of the openings in the mosque building imply maintaining the internal temperature, for this reason, in most mosques, the number and size of the openings and skylights of the external walls of the mosque are reduced to the minimum possible to control the heat exchange. The cold weather in the cold seasons of the year in the mountainous climate requires materials such as stone, brick and clay in the structure of buildings, especially mosques.

Conclusion
In the four regions of Iran, the body of mosques has been adapted as much as possible to the climate of each region so that in addition to meeting religious or political needs, human comfort needs are also provided in the space inside the mosque. Climatic factors are visible as influential factors in the structure of mosques in Hamadan city. The quality of the structural model and the materials used in Hamadan mosques have many similarities with each other due to the climate of Hamadan. In the review of 16 prominent mosques in the urban context of Hamadan, it can be clearly stated that the overall structure of the mosques does not have significant differences from each other. The plan of most mosques is often compact and square or rectangular. Most of the mosques, except Jame Mosque, Haj Kalbali Mosque and Sheverin Mosque, have a central tabernacle, and the materials used in all mosques are generally the same. Heavy materials such as brick and stone are prioritized due to their high thermal mass. All mosques have flat roofs, which causes snow to accumulate on the roof, and the only dome-shaped mosque in the city is Jame Mosque as the main mosque. The height of most of the mosques in this area is relatively short, except for the Grand Mosque. The dimensions of the openings and windows in the mosques of this area are few. The importance of the courtyard in other regions is not seen in such mosques. The layout of mosques is mostly integrated with the surrounding context such as alleys, streets, residential houses and markets, and the mosques are connected to the adjacent buildings, which is effective in maintaining the heat inside the mosques as well as the adjacent buildings.