The bridge at Sanahin is older than most of the countries in Europe. A single high arch of dark stone, it spans the Debed river just below the town of Alaverdi, a work of the twelfth century that has outlasted wars, floods and Soviet roadbuilding. It was built for the caravans that used the valley as a route between Tiflis and the Armenian highlands, and it is still sturdy enough to walk across, with a rough cobbled surface and a steep rise in the middle.
The setting is a lesson in contrasts. The canyon walls rise steeply on both sides, covered in oak and beech, and the river runs green and fast beneath the arch. Close by stands a railway line, a Soviet-era factory, and the old copper smelter that gave Alaverdi its industrial character, and the whole scene has a strangely poetic ruggedness, with the ancient bridge in the middle of it all.
Alaverdi, about a kilometre away, has some 13,000 people and the services you would expect: shops, cafés, a market and petrol stations, so this is the place to refuel. The road along the canyon is the main route between the Georgian border and Yerevan, and it is busy with lorries, which struggle on the gradients and fill the air with diesel. Pull in carefully if you stop at the bridge, and keep an eye on the river bank, which can be slippery.
Weather in the canyon is mild in spring and autumn, but summers are hot and winters cold, with snow on the surrounding hills. Mist often fills the valley early in the morning, and when it lifts, the stones of the bridge are wet and dark. It is a good place for a short stop, a photograph and a quiet moment, before the road leads on to the monasteries above.