The Barz-qawela site is among the most important Sasanian-period sites so far identified in the Kuhdasht region of Lorestan. This site was discovered during the archaeological survey of the Kuhdasht region in autumn 2008 by Amir Mansouri and was subsequently subjected to rescue excavation in autumn 2010 under the rescue archaeology project for the reservoir basin of the Seymareh Dam. During the surface survey conducted at the site, three silver and bronze coins dating to the late Sasanian period were discovered. This suggests that, in view of the abundance of archaeological remains and the many extant archaeological traces, the Ramavand plain and the Tarhan region held considerable significance along the communication route from Mesopotamia to central Iran via the Zagros Mountains. In this article, an attempt is made to examine the significance of the Ramavand plain and the Tarhan region in the late Sasanian period, alongside an analysis of the coins recovered from the Barz-qawela site.

1. Introduction
Numismatics, as a discipline capable of significantly contributing to historical research, holds a special position in the study of economic and political history. Unlike the Parthians, the Sasanians possessed a dynamic and prosperous economy, evidenced by the high purity of the metal used and the superior quality of their coins. By reforming Parthian minting traditions and reverting to some Achaemenid characteristics, they sought to legitimize their rule as the rightful heirs of the Achaemenids, distancing themselves from the 472-year Hellenistic-influenced Parthian period. During this era, the increasing importance of the east-west trade route, now known as the Silk Road, and the expansion of international commerce along this corridor, prompted the Sasanians to quickly recognize the geopolitical significance of their territory. From the very beginning of their rule under Ardashir I (224–241 AD), they attempted to establish the Sasanian silver drachm as a valid currency across vast regions, including the Middle East, Transoxiana, the Caucasus, Eurasia, Ceylon, Xinjiang, and the Indian subcontinent. The Sasanian silver drachm and the Roman-Byzantine gold solidus were recognized as two major international currencies, suggesting a form of monetary coexistence and coordination between the two powers. Although there were occasional debasements during specific periods, the silver content of Sasanian coins generally remained stable from Ardashir I to Yazdegerd III. The Sasanian drachm held such prestige that even invading nomadic groups like the Kidarites and Hephthalites modeled their coinage on the Sasanian tradition. By controlling the east-west caravan routes, the Sasanians not only increased tax revenues but also facilitated the transmission of their art and technology to surrounding regions, further enhancing the influence and credibility of their coinage. This paper examines the significance of the Ramavand plain and the Tarhan region in the late Sasanian period by analyzing coins discovered at the Bard-Ghabaleh site, one of the many late Sasanian settlements located on the entrance route from Mesopotamia into the Zagros Mountains.

2. Research Methodology
This research is classified as an archaeological and historical-analytical study, aimed at introducing and interpreting the Sasanian coins discovered at the Bard-Ghabaleh site in Seymareh, Kuhdasht, Lorestan. The primary data were collected through field surveys and rescue excavation conducted as part of the salvage archaeology project for the Seymareh Dam reservoir basin. During these investigations, three silver and bronze coins dating to the late Sasanian period were identified and recorded. Following data collection, the coins were examined and classified based on their physical characteristics, material, state of preservation, and chronological attribution. Additionally, relying on surrounding archaeological evidence and the geographical location of the site, the role of the Ramavand plain and the Tarhan region in the communication and economic network of the late Sasanian era was analyzed. The analytical approach of this research combines field data with historical sources and comparisons with similar specimens to illuminate the strategic importance of this area within the communication route between Mesopotamia and the central plateau of Iran. The site, known locally as Barz-qawela, is located in the Seymareh River basin, in the Konani district of Kuhdasht county, approximately 70 kilometers from Khorramabad, the provincial capital of Lorestan. The site covers an estimated area of over 10 hectares, situated at coordinates 47° 9' 112" E and 33° 20' 175" N, at an elevation of 637 meters above sea level.

3. Discussion
3.1. Discovery Context and Site Significance
The three coins were discovered during a surface survey in the autumn of 2008, within disturbed soils around a crescent-shaped architectural structure resembling a barrel vault, which had previously been looted by illegal excavators. It appears these coins were part of a larger collection removed by antiquities traders, likely left behind due to damage or fractures. The archaeological site of Bard-Ghabaleh is among the most important Sasanian-period sites identified in the Kuhdasht region. The abundance of Sasanian-period remains, such as bridges (including Pol-e Kashkan, Pol-e Cham-e Nam-sht, Pol-e Gavmishan, and bridge piers on the Seymareh River opposite the Sasanian city of Barz-qawela), along with existing mountain caravan routes, indicates that the Tarhan region was an integral part of the communication network linking it to surrounding territories like Kermanshah, Mesopotamia, Khuzestan, and the central plateau of Iran. This network highlights the strategic importance of this area during antiquity and the Sasanian government's attention to it.
3.2. Description and Analysis of the Coins
The three coins consisted of two silver specimens and one bronze piece. Due to heavy sedimentation and fractures, initial identification was challenging. Following preliminary cleaning, restoration, and archaeological studies, with expert consultation from Dr. Touraj Daryaee, the coins were identified.
3.2.1. Silver Coin No. 1
This coin was in relatively good condition, weighing approximately 3.68 grams. Typologically, it belongs to the group featuring the second crown style of Khosrow II. The obverse depicts the bust of Khosrow II facing right, while the reverse shows a fire altar with two attendants on either side. Based on expert analysis, this coin is attributed to the twenty-second year of Khosrow II's reign (591–628 AD) and was minted at the "NH" mint, which likely refers to Nahavand. The obverse includes the word "Khosrow" in the first quadrant and "Apzud" (meaning "increased" or "augmented") in the fourth quadrant. Earlier readings had suggested the "WH" (Veh-Kavad) mint and the eleventh regnal year, but reinterpretation favored the "NH" attribution due to similarities in Pahlavi script for the letters "w" and "n."
3.2.2. Silver Coin No. 2
This coin was fractured, making precise dating difficult. However, the word "Khosrow" is discernible on the obverse, and the reverse shows the mint mark "DA" or "Darabgerd." Despite the damage, based on the iconographic style of Khosrow's bust, it can be tentatively assigned to the middle period of his reign. The straight-line distances from the mints of Nahavand and Darabgerd to the Bard-Ghabaleh site are approximately 150 and 860 kilometers, respectively, which is consistent with typical circulation patterns.
3.2.3. Bronze Coin No. 3
This coin was heavily corroded and sedimented, but evidence suggests it belongs to a local ruler named Farrokhzad, dating to around 670 AD (51 AH), a period following the collapse of the Sasanian Empire. It features a vague image of a Sasanian king and several words in Pahlavi script on the obverse, with a probable fire altar motif on the reverse. The identification of this Farrokhzad as the brother of Rostam Farrokhzad and a close associate of Yazdegerd III, who continued to rule parts of Fars after the last Sasanian king's death, opens two interpretive possibilities: First, this coin might represent an attempt by Farrokhzad to assert political independence against the emerging Arab power. Second, considering the Arab rulers' limited familiarity with Iranian governance structures and the greater local acceptance of an Iranian governor, Farrokhzad might have been granted a degree of autonomy in exchange for paying the jizya (tribute). The date of this coin (circa 670 AD) coincides with the caliphate of Muawiyah, a period before the establishment of a fully independent Arab-Islamic coinage system. Arab-Sasanian coins, retaining Sasanian iconography of kings like Khosrow II and Yazdegerd III, were common in many regions of Iran at this time.
3.3. Historical and Economic Implications
The discovery of Khosrow II's silver coins at Bard-Ghabaleh confirms the site's connections with other parts of the Sasanian realm, supporting the likelihood that trade and caravan routes passed through this area. The presence of the Farrokhzad bronze coin further suggests either a possible, though less likely, extension of his influence into the Seymareh region, or more probably, that the coin arrived as a casual medium of exchange brought by an individual from Fars. The find illustrates the integration of the Ramavand plain and Tarhan region into the broader economic and communication networks of the late Sasanian period, leveraging the natural mountain passes of the Zagros to link Mesopotamia and the central Iranian plateau.

4. Conclusion
The discovery of these coins at the Bard-Ghabaleh site firmly establishes its occupation during the late Sasanian period. The sheer number of Sasanian-era sites and structures in the Tarhan region emphasizes its significance within the Zagros area during this historical phase. The presence of a network of bridges and roads underscores the strategic importance of this area and the Sasanian state's investment in its connectivity. The silver coins of Khosrow II confirm the existence of trade or communication links with other parts of the empire. Regarding the bronze coin of Farrokhzad, while it could indicate the region's temporary inclusion in his sphere of influence (a notion less supported by historical and numismatic evidence), it is more plausible that it was transported to the area casually as a means of exchange by an individual from Fars. Unfortunately, with the flooding of the Seymareh Dam reservoir in 2013, the site of Bard-Ghabaleh, along with numerous other historical sites in the Tarhan and Seymareh regions, was submerged. Consequently, many unresolved historical and cultural questions about this strategically vital region were permanently lost to researchers.