Oman: Falaj Daris
Falaj is a stone-enclosed irrigation channel that’s has been used in Oman for water supply since around 500AF. There are about 3000 aflaj (the plural of falaj) systems around Oman, some abandoned and some restored. Falaj Daris is the largest one of them and supplied water to the town of Nizwa and its royal fort. The aflaj water system used gravity to channel water from underground sources to towns and villages, water being the most precious resource in Oman (probably after frankincense). The Falaj Daris is a UNESCO World Heritage Site.