In 1090, Hassan-i Sabbah took the rock fortress of Alamut and made it the centre of a network of castles that held out against the Seljuk sultans for over a century and a half. The community was later known in European tales as the Assassins, a legend that grew with the telling, and the castles were destroyed by the Mongols in 1256.
The ruins of Alamut, on a long rock spur above the valley, can be reached by a steep climb up a stairway, and the view from the top over the valley, with snow-capped peaks beyond, explains why the site was chosen. Other fortifications are scattered in the valley and the passes, many known only to local people.
The riding is dramatic, if demanding. The road from Qazvin climbs into the valley through villages of stone and mud brick, with walnut and apple orchards, and the surface can be rough, with potholes, rockfalls and sections under repair. Further north, the Chalus road crosses the Alborz by a high pass and tunnels, descending to the Caspian through forest, with fog and heavy trucks. In winter, snow and ice make the roads dangerous, and in spring, landslides are common. The best months are May to October.
Fuel and supplies are limited in the valley, so fill up in Qazvin, a large city and an old Safavid capital, before you leave, and carry food and water. Local specialities include walnuts, dried fruit and honey, and a glass of tea is offered everywhere. Come with time and patience, and check the current travel advice for Iran, which can change quickly. The reward is a landscape of rock, sky and silence, with a history far older than the roads.