Gerdkuh Castle

Gerdkuh Castle, also known as Dezh-e Gonbadan, was one of the most important fortresses of the Nizari Ismailis in Iran. It lies 15 kilometres from the city of Damghan, near the village of Haji Abad Razveh. This historic monument was added to Iran's National Heritage list on 25 Esfand 1378 (SH) under registration number 2650, and it is regarded as one of the notable historic sites of Damghan. Gerdkuh Castle was built on top of a rocky plateau in the Alborz range. At an elevation of roughly one thousand metres and a length of about half a kilometre, it was one of the most heavily fortified and impregnable Ismaili strongholds in Iran.

Gerdkuh Castle dates back to the early Islamic period or slightly earlier, and it is closely tied to the history of the Nizari Ismaili state in Iran, which was active from the late 5th century AH (11th century CE) until the middle of the 7th century AH (13th century CE). By making use of the mountain's natural structure, the fortress became one of the most resilient military strongholds in Iran. Its walls, watchtowers, covered cisterns and structures of stone and sarooj (a traditional waterproof mortar) allowed its inhabitants to hold out for a long time. The cisterns and the water supply from nearby springs show careful planning for long sieges. Gerdkuh Castle resisted the Mongol siege for about 17 years and finally fell in 669 AH (lunar Hijri), an event that has made it one of the symbols of historical resistance in Iran.

The route to Gerdkuh Castle begins in Damghan. After reaching the area around Haji Abad village, the rest of the way is a mountain route that is fairly rough. The best times to visit are spring and autumn, when the weather is more suitable for hiking. Given the historic nature and fragility of the site, it is especially important to follow cultural heritage conservation principles, avoid damaging the remains of the structures, and pay attention to safety on the mountain trails.