Lamia Hassan · @LamiaHassan
17th Apr 2014 from TwitLonger
First built in the 8th century, the Nilometer was used to measure the clarity and water level of the Nile during the annual flood season. It is no longer in operation. https://www.facebook.com/ahramonline/photos/a.548383608545229.1073741825.138561829527411/719546864762235/?type=1&theater