The palace of koh-e Khwajeh in Sistan is one of the most important archaeological sites on the east of the extensive territory of the Parthian and Sassanid rules. Since the beginning of the 20th century, the site of the Koh-e Khwajeh has attracted the attention of well-known and great archaeologists such as Stein and Herzfeld, and studies of this key site have been continued continuously to this day. One of the important and controversial issues in this area is the historical sequence and function of this magnificent monument. The purpose of this research is to achieve an accurate understanding of the chronology and function of this huge site based on the studies, surveys and excavations carried out so far as well as the logical conclusions made in this regard.
The excerpt of the current research is focused on the stuccos, ceramics, paintings, and the coins obtained from this site and at the same time it is attempted to make the most use of architectural elements such as clay reliefs and also absolute dating experiments performed on this site. According to the research conducted, including the results of the absolute dating, clay reliefs and coins obtained from fieldwork suggest that this site has been of special value and importance in the Sassanid period. The site resembles the cities of the historical period in the Parthian-Sasanian eras in terms of physical and spatial structure; however, the space where was used was so limited that it could not have functioned as a city. This palace, according to the studies carried out, is very similar to Takht-e Suleiman monument in Azerbaijan and can be assumed to have functioned as a palace-temple.