Investigating the reflection of the expansion of Shiism in Khorasan and its impact on the tomb of Ali ibn Musa al-Reza (AS) in geographical and historical sources from the third century to the end of the Timurid period.

The scholars and elders of each religion are very important to their followers. The position of Imam Reza (as) and his grateful tomb have always been popular throughout the history of the people, including Muslim geographers. Also, various groups of people have always tried to maintain their religious sites. The collection of buildings and places of honor Aliben- Mussi -al- Reza (AS) is considered to be very beautiful artwork. Because in each of its parts there is a work of art. The appearance of verandahs, porches and flower beds is designed specially by architects and engineers and is made with special designs and numerous architectural, tiling, mirroring, gilding, painting, carving, calligraphy and inscriptions in the courtyard Nourani Imam Reza (AS) and his mausoleum are a reminder of the various artistic manifestations of Iran's different period from the third century AH that fascinated the wonder and beauty of the art as well as the travelers and geographers.
The present article tries to identify the viewpoints of tourists and geographers about Imam Reza (AS) with a historical, analytical and descriptive approach. In this research, first, Imam Reza (as) enters Maraw and his martyrdom and then goes to the viewpoint of travelers and geographers about their tomb. By studying the historical and analytical sources of available resources, it seems that the appearance of porches, porches and flower beds, specially designed by architects and engineers, is made with special designs,