A qanat is a tunnel with a long memory. Somewhere in the foothills a digger sank a shaft until he struck water-bearing gravel, then cut a gently sloping tunnel from the water downhill to a village, with vertical shafts every few dozen metres to let in air and haul out spoil, so that water flowed to the surface by gravity alone, without a pump and without evaporating in the sun. The Persians were doing this by the first millennium BC, and the idea travelled to Egypt, North Africa and Spain. UNESCO listed eleven Persian qanats in 2016, and the one at Vazvan, in the province of Isfahan, is among them. It is still in use, and its tunnel, hand-dug and thousands of metres long, still feeds fields and gardens.
What you can expect is a line of small mounds across the plain, like a string of anthills, each the spoil heap around a shaft. From the air they look like beads on a thread. The diggers, called muqannis, were specialised families who handed on their skills, and the person in charge of the qanat, the mirab, shared the water out fairly among the users by the hour.
The country is the high plateau of central Iran, at roughly two thousand metres, with bare brown hills, wide gravel plains and green oases wherever the water arrives. The road between Isfahan and Kashan runs through this dry landscape, with long straights and low passes, and the mountains of the Zagros stand to the south-west. The air is thin and clear, and the evening light turns the hills pink and violet.
Riding on these roads is easy but remote. Surfaces are generally fine on the main routes, but trucks are heavy, and the wind raises dust. Villages are far apart, so carry water and fill the tank when you can, since fuel stops are spaced widely. Spring is best, when the plain is briefly green and the almond trees are in bloom, and autumn is also good. Summer is very hot, and winter can be snowy at this height. Check the rules for travel and for entering the country, which are complicated for visitors. A glass of sweet tea at a village stall is the best way to end the day.