Nizwa lies at the foot of the Hajar mountains in the interior of Oman, and its date groves exist because of a method of bringing water that is older than the town. The aflaj, plural of falaj, are channels that carry water by gravity from mountain springs or underground sources to fields and villages, sometimes for many kilometres. UNESCO listed a group of five in 2006, among them Falaj Daris, which feeds Nizwa and is one of the largest in the country. Some aflaj are believed to be very old, perhaps thousands of years, and they are still in use, with the water divided among families by time, measured by sundials in the daytime and by the stars at night.
You can follow the channel from where it emerges and watch the water slip along the stone-lined course, past mosques and little gardens, until it splits into small channels to feed date palms, pomegranates, lime trees and alfalfa. The coolness and shade of the oasis, after the dry hills, is like entering another climate. It is a sociable system, too: an official oversees the distribution, and arguments are settled by custom.
In Nizwa itself you should visit the great round tower of the fort, built in the seventeenth century under the Ya'ruba imam Sultan bin Saif, with views over the palms and the old market. On Friday mornings a livestock market is held nearby, a lively scene of goats, cattle and loud bargaining. The halwa shops, selling Oman's sticky sweet, are a local tradition, and the old souq is the place for silver and daggers.
The road from Muscat is a pleasure: about a hundred and sixty kilometres of good highway through the gravel plains and past bare, jagged mountains, with reasonable traffic and a few speed cameras. The Jebel Akhdar road nearby is a steep climb with a police checkpoint and, for safety, a restriction to four-wheel-drive vehicles, so check before you set out. Summer is extremely hot, with temperatures often over forty-five, so choose the cooler months from October to March. Nizwa, with over seventy thousand people, has plenty of fuel, cafes and hotels.