Location – Gorno-Badakhshan Autonomous Oblast, Ishkashim district. 178km from Khorugh, 72km from Ishkashim, next to Yamchun village.

Transportation – Khorugh-Ishkashim bus service; further by hitchhiking or taxi.

At the end of the first millennium B.C. construction of strong fortresses began in the West Pamirs due to the threat of military attacks by neighbours. The first was the Yamchun fortress (near the present-day village of the same name, also known as Zamr-i-atashparast or Kafir-qala) built in the 3rd century B.C. on the right bank of the Panj River in the foothills of the Vakhan range.

It stands on a cliff continually washed by tributaries of the Panj – the Yamchun and Vikhut Rivers – the steep banks of which are inaccessible the whole year round. The slope was used in planning the fortress. It was built in a triangle shape with its base pointing into the valley, and consisted of three parts – a citadel, a bastion and the barracks surrounded with walls and strengthened by rectangular towers and two squares, each of which was also surrounded by high walls, fortified with 36 rectangular and oval towers with embrasures (portholes). In case of attack a huge number of people could hide inside the fortress. The walls have no foundations and they are made of machine-tiled stones on a solid clay base.

The total height of the walls is about 3m and the width about 1.5m. There are portholes in the walls at various heights: the height and width of them ranges from 30–55 cm, and the distance between them is 1.5-2.5m. The portholes get wider from the outside. There are 2 sets of fortress walls, one inside the other. The outer wall, up to 2m thick, is either made entirely of stones, or of stones in the lower part and unbaked bricks in the upper part. The inner wall is similar to outside one, but is only 50–60cm thick. It also has crack portholes directed inside the fortress. The distance between the outer and inner walls is about 2m. When constructing the walls the builders interlayered the stones with thin beams to make the walls firmer in places, and today one cannot help but admire the skills of the ancients who made the walls and towers earthquake-proof. All the walls are connected by a chain of towers equipped with thin portholes about 1m high and approximately 30cm wide, arranged like a chessboard in a staggered order with a few layers covered with slightly-angled tiles to allow marksmen in the fortress to defend the Panj valley from several sides. The towers are about 3.5–4m in diameter, the walls are 1-1.5m thick, and the distance between the portholes is 2-5m.

The towers were constructed with stones with occasional clay grout and in some places covered by clay plaster. The upper side of some of the towers is made of baked bricks. Most of the towers are equipped with portholes pointing outwards as well as inwards, and even inside the inter-wall corridors and compartments, which considerably increases the defensive capability of the towers and, hence, the fortress. Thus, defenders of the fortress were always able to attack enemies from the rear if the outer line of defence was broken through. Stones for constructing the fortress (there are hundreds of thousands of them) must have been brought from various remote areas, since there were metamorphic rock, granite and slate rocks, biotite pieces and other forms of mica.

The size of the fortress is striking. This powerful structure was of the greatest importance for the area. Defending against approaches from every side, it was a strategically placed and well-built complex that allowed the supervision of people and shipment flows from the Pamirs to ancient Bactria (Tahoriston), India and Iran and back. However, some aspects of the fortress are puzzling: the Panj valley, with a 2.5-3km wide river floodplain next to the fortress, is absolutely flat, and the Panj flows down not against the northern but the southern slope of the mountain. How could ancient people shoot into the valley with arrows – which were most likely the main weaponry at that time – during enemy attacks? An arrow’s range is not very long. Perhaps the Panj River at one time ran closer to the right-bank slope, even propping it up. This question remains unanswered. Today one can reach the fortress by vehicle. From the main road, coming from Ishkashim, you need to turn left towards Tuggoz village, and then continue 5-6km up along a rather steep village road to Yamchun village, which is located beside the main road on the mountain slope.

There is a hot radon spring 1-2km from the fortress. Medicinal water wells up from under the mountain at a temperature of 40-42ºC. The water is useful for treatment of gastro-intestinal, liver, gall-bladder, joint, bone, musculoskeletal, urological and gynecological disorders. There is a sanitarium half a kilometer from the spring where one can stay overnight.