The aqueduct's arches glare at the viewer, watching while watched, absorbing attention and hiding what hides behind. Ain Al-Sira, for those who don't know, is one of Cairo's many shantytowns. In it, as one would expect, reside Cairo's poorest.
Some residents work there.
Others commute, from dawn to dawn, to and from the centre of Cairo. Knowledge of its presence amongst the locals radiates and almost glows from it. Try and seek it out alone and you'll fail. Ask almost anyone in the area and they'll direct you straight to it. Here, as an alternative to our opening answer, a child is defined as someone between the ages of five and 15.