Tarbiat Modares University The International Journal of Humanities 2538-2640 33 1 2026 01 01 A Study on the Functional Analysis of Achaemenid Sites along the Hirmand River in Eastern Ancient Sistan (Helmand and Nimruz Provinces, Afghanistan) 28533 10.48311/eijh.2026.118122.82824 EN Javad Alaei Moghadam Assistant Professor, Department of Archaeology, Faculty of Art and Architecture, University of Zabol, Zabol, Iran 0000-0002-2857-890X Sharifeh Sargolzaei Assistant Professor, Department of Urban planning, Faculty of Art and Architecture, University of Zabol, Zabol, Iran 0000-0003-3713-4689 Journal Article 2025 12 05 The Hirmand River, as the largest river in the eastern Iranian Plateau, has played a significant role in the formation and expansion of civilizations and cultures in Greater Sistan in eastern ancient Iran. In the last century, limited surveys have been conducted in the eastern part of the Hirmand River basin (the ancient provinces of Helmand and Nimruz, Afghanistan), each covering a portion of this region and introducing sites from various historical periods. Unfortunately, due to the prevailing insecurity in Afghanistan, studies in the eastern Sistan region have remained incomplete, leaving many ambiguities regarding various historical periods, including the Achaemenid era in this area. Therefore, in this research, which was conducted with the aim of investigating the function of Achaemenid sites around the Hirmand River in eastern ancient Sistan, we first introduce and study the Achaemenid ancient sites along the banks of the Hirmand River based on archaeological reports and remote sensing via satellite imagery. Subsequently, by analyzing the obtained data, the Achaemenid sites along the banks of the Hirmand River are examined in terms of their function. The results indicate that across the five archaeological survey projects conducted in the eastern part of the Hirmand River basin, 19 sites contain evidence from the Achaemenid period. Based on the study of characteristics such as site area, geographical location, topographical condition, and architectural remains, it can be stated that a number of the Achaemenid sites along the banks of the Hirmand River are the remains of garrisons or waystations (a type of caravanserai) that guarded one of the ancient routes in the eastern Achaemenid Empire and the caravans that traversed it. The other Achaemenid sites in this region represent small villages that were established along the banks of the Hirmand River. https://eijh.modares.ac.ir/article_28533_3b0de458c502917011cdb5292f078c7a.pdf