At the foot of the Hajar mountains, near the old town of Birkat al Mouz between Izki and Nizwa, the Falaj al Khatmeen is one of five Omani irrigation systems listed by UNESCO as the Aflaj Irrigation Systems of Oman. A falaj is a channel that brings water from a spring or an underground source, sometimes kilometres away, to villages and date gardens, and this one has been running for centuries. What makes the aflaj remarkable is the system of sharing: the water is divided among the owners of shares by time, traditionally measured by the shadow of a sundial by day and the movement of the stars by night, and the rules are managed by the community with great precision. Walking along the narrow stone channel, with fish darting in the clear water and the shade of the palms overhead, you feel the coolness that comes from water in the desert.
Birkat al Mouz has a ruined old quarter of mud-brick houses climbing the slopes behind the gardens, and a restored fort. The mountains behind rise steeply to the Jebel Akhdar, the green mountain, a high plateau with terraced gardens of roses, pomegranates and walnuts, famous for the rose water that is distilled in spring. The road up to the plateau begins nearby and climbs in a long series of steep bends; there is a police checkpoint at the bottom that controls access to the plateau, so check the current rules for vehicles before you go.
Riding in Oman is a pleasure in the cooler months, from October to April. The roads are excellent, smooth and well signposted, traffic is generally disciplined, and the mountain scenery is spectacular, with bare rock in shades of brown, grey and purple. In summer, temperatures are brutal, and riding in the middle of the day is unwise. Watch for speed cameras, which are very common, and for camels and goats on the road outside towns.
Nizwa, about fourteen kilometres away, is the big town of the interior, with its massive round fort, the souk and the Friday livestock market, an extraordinary sight early in the morning. It has fuel, hotels and restaurants, as does Izki. Try Omani halwa, a sticky sweet flavoured with rose water and saffron, served with bitter cardamom coffee and dates, a ritual of hospitality you will encounter everywhere.