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 economic boom, the so-called Miracle on the Han.

I’m panicking. There’s no place to go. We cannot move to other places – this is an ecosystem Kim Hak-ryul

But even as the tour guides at nearby Jongmyo Shrine extol the history, foibles and eating habits of the long-dead Joseon dynasty, here in Euljiro a living history is about to be unceremoniously wiped out.

Q&A Where are the next 15 megacities? Show Hide By 2035 another 15 cities will have populations above 10 million, according to the latest United Nations projections, taking the total number of megacities to 48. Guardian Cities is exploring these newcomers at a crucial period in their development: from car-centric Tehran to the harsh inequalities of Luanda; from the film industry of Hyderabad to the demolition of historic buildings in Ho Chi Minh City. We'll also be in Chengdu, Dar es Salaam, Nanjing, Ahmedabad, Surat, Baghdad, Kuala Lumpur, Xi'an, Seoul, Wuhan and London. Read more from the next 15 megacities series here.

Nick Van Mead

Seoul is growing fast. Although the city will only enter the United Nations’ official list of megacities – those with more than 10 million residents – in 2024, the wider metropolitan area is already home to 25 million.

Euljiro against the backdrop of newer and taller buildings

In October, the city government gave the green light to Hanho Construction to knock these shops down, as part of a huge plan to redevelop the area around Seoul’s popular Cheonggyecheon stream. The shopkeepers will be evicted and the ecosystem of 10,000 shops destroyed. Apartment buildings will be erected in their place. The process has already begun.

“I’m panicking,” says Kim Hak-ryul, 60, whose shop, Shina Casting, makes iron moulds. “There’s no place to go. We cannot really move to other places – this is an ecosystem.”

Most of the shops in Euljiro sell primarily to each other, working together to solve problems and build prototypes for the industrial and electronics sectors that are so important to the South Korean economy.

Kim Hak-ryool (left), and Mr Baek in their metal workshops

“This area is all handmade. It’s a critical place for making samples for big companies like Samsung or LG,” says Kim, who took the shop over from the founding Shina family 15 years ago and kept the name out of pride for its long heritage.

“We can do very diverse work for very small amounts. This is the one place you can do it quickly. If you want something, we can make it in a day or two – probably it would take a month in the US or other countries. We are very quick and very cheap. So the value is very high for Seoul citizens and the industry – but Seoul municipality doesn’t understand that.”

Under the terms of the Sewoon Sangga regeneration project, the shops are being compensated for four months’ worth of revenue. Given many of them conduct business in cash, they are likely to receive much less than their true value. Nor can they scatter around the city and expect to survive: many landlords aren’t keen on dirt and noise, and moving would also separate them from their biggest clients – each other.

Jang Jong-il, 60, in his wooden model workshop in Euljiro

These shops are a key part of Seoul’s healthy functioning, past and present, says Park Eun-seon, urban activist and founder of the collective Listen to the City.

“This area is now the oldest area in Seoul. Everything else is postwar. Here we have some originals. The people worked here for a long time, making their own history – and now the government wants to make it offices and apartments. Ridiculous.”

She points out that the government has past form in demolishing first and asking questions later. In 2003, when the Cheonggyecheon stream was originally developed, more than 30,000 street vendors were moved out after an elevated highway was demolished to restore the original river underneath. The waterway is now a favourite socialising spot for Seoulites, and its success helped propel then-mayor Lee Myung-bak to the presidency.

But the area around the redeveloped stream is also prime real estate. It stretches roughly 10km from City Hall in the west to Dongdaemun Design Plaza, a spaceship-like exhibition hall designed by Zaha Hadid. Euljiro is caught in the middle.

Inside the workshops of Euljiro

Park worries that the fight will end in violence, like many previous regeneration projects. In 2010 six people, including one policeman, died in a fire during an eviction, and then next year she and her peers occupied the Mari Cafe, one of the Euljiro restaurants slated for demolition.

She says anonymous thugs came to threaten them every night, demanding they leave: “They beat you, and swear at you, and pee, and throw poo. In front of ladies they take down their pants and pee in front of you.”

On 3 August 2011, they stepped it up. “It was a terrible night. We did a film exhibition in the Mari Cafe. So they sent 200 thugs. And then we get beaten, and policemen shut the door. Can you believe that? We were inside to protect the building, because … you have to occupy it, you have to squat it. Two hundred gangsters came in and [the police closed the gate]. It was a mess. Many people got injured.”

The ‘thugs’ who beat up activists trying to occupy the Mari Cafe in 2011

There are no signs of violence in the current dispute, nor any suggestion that Hanho Construction was involved in any past confrontations, but the Korea Times has reported that the firm has sent aggressive letters to shop owners, bypassing their official tenants’ association. Many of the letters asked for double rent, or claimed damages of up to 500m won (£343,000) for unspecified obstruction, the newspaper said.

“In Korea, this urban substance is still very volatile, very fragile. It could be wiped out depending on any political regime,” says Minsuk Cho, an architect who returned to Seoul from New York in 2003 to establish the firm Mass Studies.

“This is still unfortunately a country addicted to real estate. It’s so sad that young kids nowadays, [if you ask them] what do you want to be in the future, it used to be president and astronauts, now it’s like, ‘I want to be a building owner.’ It’s neo-feudal. Or a K-pop star …”

However, he does sees some cause for optimism in Korea’s history of protest. In 2016, for example, a series of demonstrations in Seoul against corruption swelled to more than 2 million people, according to organisers’ estimates.

Demolition in progress

“It was like Rio carnival,” Cho recalls. “People are really fed up, but they develop this mass expression, [and express] their common interests and common concerns in a very festive way. You think [South] Korea is just another Asian country that’s really top-down, but we’re really not like that. Although something like a quarter of GDP is from Samsung, and half of national GDP is by these mega chaebol business conglomerates, we still have a country full of tiny shop owners who like it that way – they like the autonomy.”

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That David-and-Goliath tension may be coming to a head in Euljiro. In January, following several protests in front of City Hall and a public outcry over the fate of a few well-loved restaurants, the mayor, Park Won-soon, a former civic activist himself, announced a formal review of the regeneration plan. Although the redevelopment has not been cancelled, he has asked a commission of experts to suggest alterations.

The obvious alteration would be to renovate the area rather than knocking it all down, suggests Kim of Shina Casting.

“I don’t understand why they’re destroying everything,” he says. “Everyone here has very different skills – 30- and 40-year-old skills – it’s unique. We are a community, and this is destructive.”

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