Features and Function of the Stone Staircase at Qal’eh Sang in Sirjan Based on the Archaeological Excavations and Historical Sources

The old city of Sirjan developed during the 11th – 15th centuries in the Qal’eh Sang near the modern city of Sirjan. There is a limestone staircase with an inscription on the northern slope of Qaleh Sang. Various hypotheses have been made about its function, such as a Minbar or pulpit for a mosque from the Muzaffarids period, or an artifact related to the fire-altar. In the excavation at the Qal’eh Sang in 2015 new information was obtained about the staircase that is important for evaluating previous hypotheses. The question is what was the process of formation, changes, and functions of the stone staircase in the Qal’eh Sang? This paper deals with the results of the excavation at Qal’eh Sang and the study of historical sources. The results show that this artifact was not a staircase form before 789 AH/1387 CE. Therefore, it did not resemble the stone stairs of the fire-altar in Pasargadae. An inscription was first created on this artifact in 789 AH/1387 CE, and then its stairs were carved. Furthermore, no evidence of the mosque was found in the excavation around the staircase. Therefore, it was not an insitu Minbar or Pulpit. The north slope of Qal’eh Sang lay outside the Gate and was, therefore, on the outskirts of the city. This area has become a hewing workshop after the decline of the city. This stone artifact was probably made as a memorial to Sultan Ahmad, the Muzafarri ruler. It seems that the carving process of the Minbar was still in progress after the Timur’s invasion, but was never completed.