problems of juvenile delinquency.
Given this description of a city,and asked to place it geographically and chronologically, many people might be tempted to guess 20th-century California; on the evidence it would be a reasonable supposition.
In fact this is an accurate description of a city that flourished in China nearly 1400 years ago, at a time when London was the tribal capital of the East Saxons,and little more than a collection of huts; when Paris consisted of a few churches with ramshackle dwellings huddled around them; and when even Rome, once the sovereign city of the western world, had been reduced by successive barbarian invasions to little more than a provincial shantytown.