Wadi Hanifa

The valley runs for a length of 120 km (75 mi) from northwest to southeast, cutting through the city of Riyadh, the capital of Saudi Arabia.

Its current name is derived from that of the Banu Hanifa, the principal Arab tribe in the area at the time of the Islamic conquest of Arabia.

This is reflected in the local folk tradition that claims that during the reign of the ancient kingdom of Al-Yamamah, the area was once covered with oases and fertile farmland.

The nature of the dry, warm climate leads to a high percentage of the scarce rainfall being instantly evaporated.

While abundant, the levels of the water table are being tested by the rapid growth the city of Riyadh has seen in the past fifty years, from a population of 150,000 in 1960 to an estimated 5 million today.