From the main street, the Euljiro neighbourhood doesn’t look like much: some shabby retail stores, cold-noodle restaurants, a Starbucks. Enter one of the small alleys, however, and you’ll find yourself in a kind of manufacturing anthill: thousands upon thousands of shops, each crammed to the rafters with bolts, circuit boards, iron castings, gauges, wires, lights, switches, tools and innumerable tiny objects that defy description. This incredible warren of machinists is the manufacturing heart of Seoul. There are 10,000 shops here, with 50,000 tradespeople, many of whom have been working here since the 1950s and were integral to South Korea’s postwar...