Below, car horns bellow tuneless symphonies amid avenues of faded 19th-century grandeur while donkey carts rattle down dusty lanes lined with colossal Fatimid and Mamluk monuments. This mega-city's constant buzz and noise is a product of its 22-or-so million inhabitants simultaneously crushing Cairo's infrastructure under their collective weight and lifting its spirits up with their exceptional humour. A visit can jangle your nerves, but it's a small price to pay to tap into the energy of the place Egyptians call Umm Ad Dunya – the Mother of the World.