CIUDAD NEZA, Mexico (Thomson Reuters Foundation) - Even if Eloisa Vasquez Morales had enough money to leave Ciudad Neza, once a sprawling slum and now a scrappy suburb east of Mexico City, the young mother says she would stay.
So would Juan Francisco Perez Buendia, a government housing official, as well as Carlos Rodriguez and Victoria Gomez Calderon, a retired couple relaxing outside their neatly whitewashed house and garage.
"I believe that I am here for a reason. If I am going to do better for myself, I also want that for my community," said Morales, 30. "I want to support them."
By staying in Neza, once a dried-up lake bed of shanties set up after World War Two, residents have built a community of contrasts, where the comfortable and the destitute coexist.
Neza, now home to 1.2 million people, is an example of how slums - rather than being bulldozed - can be supported and upgraded to create thriving suburbs.
Trim homes sit alongside hovels covered with tattered rags, and horse-drawn wagons filled with garbage clatter past shiny late-model cars.
This, say experts, is the urbanization of the future.
Nearly 900 million people live in slums worldwide - or a quarter of the world's urban population, according to the U.N.
Historically in Latin America and the Caribbean, slum upgrading - as opposed to demolition and reconstruction - has been an important strategy in providing housing for the poor. Today, 24 percent of the region's urban residents live in slums.
Far from ideal, Neza is shabby, poorly served by schools, transportation and health care and is considered extremely dangerous, even by Mexican standards. Yet it holds lessons in growth and resilience for other cities, according to experts.
"The story isn't, 'Oh dear, dear, what a terrible slum.' In a way, it's a success story, in spite of the present problems," said Priscilla Connolly Dietrichsen, a professor of urban sociology at the Universidad Autónoma Metropolitana in Mexico City.
Ciudad Neza, short for Nezahualcóyotl, sits on the bed of Lake Texcoco, drained to combat flooding over hundreds of years. Too salty for farming, the dry land was taken up by developers who laid out a grid of streets and sold off boxy parcels, mostly without proper title.
In a burst of urban migration in the mid-20th century, new arrivals to Neza set up shacks of wood and cardboard, without electricity, a sewage system or running water, schools or paved roads. A bus came by every two hours or so, old timers say.
"We had to suffer for a long time, because there was a lot of mud, a lot of bugs, a lot of garbage," said Gibeto Garcia Jeronimo, 66, who has lived in Neza for four decades.
"Now I like it," she said. "Now we have garbage services. We have water, we have sewage, and they've fixed up the roads a little."
When Victoria Gomez Calderon, 82, moved to Neza from eastern Mexico as a young woman, the putrid remains of the lake were just a half block from her tiny home.
"It was a pure wasteland," she said.
Residents banded together to demand services in the 1970s, and a government programme to formalise ownership provided land titles, experts say.
Neza's reputation as the world's largest slum, coined when its population was combined with two other blighted areas decades ago, no longer applies, they say.
"Neza, it's a success in a lot of ways, in a way that like every other suburban development post-World War Two has been a success," said Michael Waldrep, a documentary filmmaker who has done extensive research in Mexico City.
"Millions of people have been given a place to live that they can call their own, that they take care of, and they have a community," Waldrep said. "You have to give credit to tireless, anonymous activists who worked for decades to make this into a functioning place."
That spirit remains, said Maria del Carmen Moreno Moreno, 50, who is adding an extra room and bathroom to her house in Neza, where she has lived since she was a small child.
Neighbours get together to buy water from a visiting "pipa" truck each week, she said.
"We're very united. If someone has a problem, we can give them a helping hand," she said. "I support my neighbours."
Whether by choice or lack of choice, residents of Neza tend to stay put, experts say.
"Family is very strong. It's not like Western Europe and the States where as soon as anybody's got a bit more money, they move house. They don't do that," said Dietrichsen.
Even educated residents may find few opportunities elsewhere, she said.
"The mother may be a domestic worker, the daughter may be a secretary, the granddaughter may have a PhD in something," she said.
Yet a lingering stigma surrounds Neza, with a reputation as a dangerous, high-crime area, said Mirna Andrade, 43, who runs the Xocoyotzin Community Center for Children.
People say "Watch your stuff because he's from Neza," and a common saying is "Thieves return to sleep in Neza," she said.
The Xocoyotzin centre is one of several daycare centres started by local mothers that now receives help from the global charity Save the Children. The parents are labourers, factory workers, gas station attendants or seamstresses who pay typically 800 pesos ($41) a month for childcare.
Residents say Neza needs much better schools and more local jobs. Many people make long commutes, riding battered microbuses through choking traffic to catch trains at an outlying eastern tip of Mexico City's subway system.
But Neza is absent from tourist guides proposing excursions outside the city limits and its worst-off denizens hunch over open fires in front of lean-tos.
Scavengers paw through trash while teenagers, identified by locals as drug dealers, stand guard on street corners. Many homes do not have running water.
The experience of Neza's bottom-up development can serve as a model for other blighted urban areas, said Jose Castillo, an urban planner and architect in Mexico City.
Its lack of zoning, for example, means Neza is teeming with micro entrepreneurs working from home or sharing spaces in what would be called co-working in trendier places, he said.
"My argument is let's stop asking what urban planning can do to fix the city and let's focus on understanding where we could also learn from those processes," he said.
"There's a strong sense of pride in place. It's a community based on the notion that jointly these people transformed this territory."
Juan Francisco Perez Buendia, 42, a lifelong resident who works for the State of Mexico's Institute of Housing, joked that people throw a lot of parties in Neza.
"That's a good reason to live here," he said with a smile.
But seriously, he added: "There are people who effectively have the resources and could go live in another secure place.
"But really, I think they like it, they like Neza," he said.
Reporting by Ellen Wulfhorst, additional reporting by Anna Yukhananov. Editing by Paola Totaro and Ros Russell. Please credit the Thomson Reuters Foundation, the charitable arm of Thomson Reuters, that covers humanitarian news, women's rights, trafficking, land rights and climate change. Visit news.trust.org