The Trans-Iranian Railway is one of the great engineering projects of the twentieth century. Built in the 1930s on the orders of Reza Shah, it links the Caspian Sea in the north with the Persian Gulf in the south, a distance of about 1,400 kilometres, across mountain ranges, deserts and gorges. The route climbs through hundreds of bridges and tunnels, often using spiral tunnels to gain height, and it was built by engineers from many countries, including Germans, Austrians and Danes. UNESCO listed it in 2021, and Yengeh Emām, in the plain west of Tehran, lies on its line.
The surrounding country is the fertile plain of Alborz province, between Karaj, a sprawling city of well over a million people, and the town of Nazarabad, with more than two hundred thousand. Orchards, poplar lines and market gardens lie among the new suburbs, and the Alborz mountains rise to the north, their upper slopes white with snow until late spring. In the old days this was farmland supplying Tehran, and traces of the older landscape survive in the villages.
For riders, Karaj is the gateway to one of Iran's classic motorbike roads. The Chalus road, which climbs from Karaj over the high Alborz and drops to the Caspian coast, runs along a deep valley and past a large reservoir, then through tunnels and a mountain pass at more than two thousand metres, before plunging into the green forest of the north. The scenery changes in a few hours from dry gravel to dripping woodland. The road is busy at weekends, when half of Tehran heads for the sea, and surfaces vary. Go on a weekday if you can, and expect fog on the northern side.
Nazarabad, ten kilometres away, has plenty of fuel and food, and Karaj has all the services of a large city. The traffic in the plain is heavy and fast, so ride with care. Travel conditions for foreign visitors are changeable, so check before you plan anything. If you are able to go, a tea and a pastry at a station cafe, with the line running behind, is a good way to end the day.