Here’s some “flavor” text from the book Metropolis: A History of Humankind’s Greatest Invention by Ben Wilson.
This is about the great city of Baghdad:
“The Abbasid caliph al-Mansur had traced out in cinders on bare earth the outline of what he ordained to be the intellectual, spiritual and commercial capital of the world.
Purpose-built with the most sophisticated and dazzling urban design by an army of 100,000 architects, surveyors, engineers, carpenters, blacksmiths and labourers, the city was complete a mere four years after al-Mansur had founded it in 762. Within a few decades its population breached the million-person mark and at its zenith perhaps had as many as 2 million.
An admirer of Euclid, the Abbasid caliph al-Mansur decreed that his city be perfectly round. The circumference of the massive wall was pierced by four equidistant gates. Four perfectly straight roads led from these gigantic gates to the centre, a circular city within the circular city. The people of Baghdad could see the enormous green dome of the imperial palace and the Great Mosque within this round precinct.”
The real city, the city where people lived and worked, sprawled outside the walls of the circular metropolis. Baghdad was a city of many cities. Al-Mansur’s master urban planners placed four large districts outside the Round City, densely populated quarters with avenues, streets, apartment blocks, shops, mosques, gardens, hippodromes, bathhouses and souks.
‘Everything produced from the earth is available there,’ wrote Du Huan, a Chinese prisoner. ‘Carts carrying countless goods to markets, where everything is available and cheap. Brocade, embroidered silks, pearls and other gems are displayed all over markets and street shops.’ A writer describing the city in its prime recorded that ‘Here every merchant, and each merchandise, had an appointed street: and there were rows of shops, and of booths, and of courts, in each of those streets.’
The markets contained the wealth of the world: earthenware and porcelain from China; silks, carpets and fabrics from central Asia; plums from Shiraz; quinces from Jerusalem; Syrian figs; Egyptian pastries; Indian pepper and cardamom; east Asian spices. There were streets and souks reserved for livestock, horses, slaves, precious metals and stones, jewellery, carpets, carpentry, hardware, fish, bread, puddings, cheeses, sweetmeats, soaps and detergents, herbs and spices, and just about everything, in its allotted space, that the heart could desire. Watermelons for instance, packed in snow to keep them fresh, were express-couriered from Bukhara.”