This is my canonically reproduced map of Roman London ca. 125 CE, jointly with Colchester. London had a population of 60,000 at the time; and Colchester circa 30,000. However, London was settlement focused on trade, while post-Iceni Colchester became a resort town for the Roman (and Romanised) elite.
Britannia is thriving under the glorious rule of Hadrian, and Pax Romana led to the acquiescence of Britons. The northernmost Roman city worthy of the status, built beyond the Thames (Tamesis) estuary holds inhabitants from all over the Empire.
It houses the largest urban military garrison in the province too. Governing this land, where the threat is constant yet uncertain, requires diligence and true political ability. Thus, the coffers of the Empire allowed for a palatial residence for the Governor (Cannon Street).
West of the forum, just by the military fort (Moorfields), lies the amphitheatre (Finsbury Circus) where plebs and patricians alike observe the Celtic warriors display their prowess against opponents from far-flung edges of the Empire. The city's biggest bathhouses are just a stone-throw away.
Across the river is a settlement, connected by the only bridge and fuelled by the easy docking points which generate trade and industry.
North of Londinium, there is Camulodunum. It lies in the plains beyond the hills, in the former home of the Iceni. It is now a patrician haven in Britannia. It boasts the only chariot circus in Britain, as well as the largest temples of the province with plenty of arenas, theatres, and bathhouses. All to cater for the prestigious Romans and Romano-Britons who live and serve the glory of Rome.