Falaj Daris is the largest and most famous of Oman's traditional aflaj — gravity-fed underground irrigation channels that have watered the country's date palm oases for over 1,500 years. It is one of five aflaj inscribed by UNESCO as World Heritage in 2006.
A short park has been laid out at the head of the falaj on the northern edge of town, where you can see the open channel carrying clear, cool water from springs underground. Follow the channel south through the date palm groves; the water is divided downstream by the falaj keeper according to ancient time-shares for each farmer. The technology is the same one used in the qanats of Iran and the foggara of the Sahara.