Cairo
The Nilometer on Rawda Island was built in 861 under the Abbasid caliph al-Mutawakkil to measure the height of the Nile flood, which decided the year's…
The Nilometer on Rawda Island was built in 861 under the Abbasid caliph al-Mutawakkil to measure the height of the Nile flood, which decided the year's harvest and taxes. It is one of the oldest Islamic structures in Egypt still in its original form. A marble column marked with measures stands in a deep stone shaft, reached by a staircase around its walls, with tunnels that once let in the river. The pointed arches of the shaft are among the earliest of their kind, and the shaft is covered by a conical roof at the southern tip of the island, beside the Umm Kulthum museum.