In 1882 the total street surface of Cairo covered only 200 kilometers. In 1900 it was 1,300 kilometers and 27 years later the street surface ran to 3,400 kilometers. Now, 80 years later, I estimate that figure at least has tripled. The beltway alone that was recently constructed is 100 kilometers long. Then there are the bridges, a tunnel and viaducts, as a result of which some streets count twice. But if I assume that there are indeed three times as many streets today as there were in 1927, then the total street surface would cover at least 10,000 kilometers. This would mean that if I wanted to learn Cairo by walking all its streets at least once, I'd have to spend one year walking 30 kilometers a day down streets where I've never been before.