Photography/Text: THOMSON REUTERS FOUNDATION/Anastasia Moloney
Huge gaps between the rich and poor, high levels of crime and social exclusion are a scourge most Latin American cities face.
To address such problems, Colombia's second city of Medellin has invested billions of dollars in the past decade on social development projects and urban renewal.
Medellin's push for urban regeneration has earned the city of 2.5 million people numerous accolades.
In 2012, for example, Medellin was named the world's most innovative city by the Urban Land Institute.
It's a dramatic turnaround for a city that was once home to the world's highest murder rate – 380 murders per 100,000 people in 1991.
Much of the violence back then was blamed on native son and drug lord Pablo Escobar, who ran the world's largest cocaine cartel until he was gunned down on a rooftop in 1993.
With Medellin no longer Escobar's fiefdom, the city has been able to reinvent itself by focusing on visionary urban renewal, most notably in once no-go slum areas.
Yet gang violence, particularly extortion payments, imposed by criminal groups still plague gang-controlled impoverished areas.
But few residents living in slum areas would deny that large amounts of political will and cash been injected into these deprived neighbourhoods, which in the past were simply left to fend for themselves.
The paisas, as the locals are known, don't have a bad word to say about what is perhaps the city's most successful and eye-catching transformation.
Launched in 2004, cable cars ferry nearly 40,000 people a day from the hillside shantytowns to the downtown below in less than 15 minutes.
Residents say the network of cable cars offers a cheap, safe and efficient way of getting around. Moreover, it has meant paisas living in deprived neighbourhoods feel connected with the rest of the city.
The cable cars link to Medellin's spotless metro system where guards will tell you off for eating or drinking.
The gondolas have also spurred urban renewal around the cable-car stations. New pavements and steps have been built.
Small businesses have also sprouted up, such as fruit and juice sellers, to tap into the flow of people passing through.
Medellin's cable cars have inspired similar transport systems in other Latin American cities, including Quito, La Paz, Rio de Janeiro and Caracas.
In the poor neighbourhood of Comuna 13, it's impossible not to miss one of Medellin's most controversial projects – the electric escalators.
Launched in 2011, a series of free and covered escalators run through the slum, which have become a tourist attraction.
It means around 12,000 residents now have a five-minute ride instead of a steep 350-step climb to reach their homes at the slum's upper reaches.
But at a cost of $7 million and disconnected from the rest of the city's bus and metro network, some local residents say money would have been far better spent on job creation and building new homes and health clinics.
On any given day, it appears there are more tourists riding the escalators than locals.
Many credit the city's transformation to Sergio Fajardo, a former mayor of Medellín (2003 to 2007), who is now governor of Antioquia, the province of which Medellin is the
A charismatic mathematician and son of an architect, Fajardo believes transport systems, education and good use of urban and public space are tools to help communities integrate and foster a sense of civic pride. It's a vision that three successive mayors have shared.
Along with a long-term master plan, experts also say Medellin's success lies in using a mix of public and private funds to finance urban development.
Medellin's makeover has been partly funded by the profitable regional utilities provider Public companies of Medellin (EPM). The energy company is owned by the city and hands over some $450 million a year for development projects.
Numerous new schools like the one above have been built near or in the heart of slums.
Over the years, the mayor's office has hired renowned architects to build provoking architecture, including kindergartens and public libraries, in deprived areas.
By doing this, mayors believe it's possible to promote social change by bridging the gap between rich and poor and bringing state services to once ignored impoverished areas.
Popular at the weekends and evenings, open-air gyms are being built alongside sports grounds in the middle of slum neighbourhoods.
The aim is to allow residents to reclaim and enjoy areas that were once abandoned or controlled by gangs.
A signature initiative of Medellin's current mayor, Anibal Gaviria, is the 56 km (35 mile) green belt.
It will act both as a buffer to contain further slum sprawl and a forested park through which residents can stroll and cycle.
Along with the jobs the project is providing, resident says they feel a sense of belonging and pride as they contribute to the transformation of their own neighbourhoods and improve their quality of life.
They also say the network of paved paths and steps, drainage canals, vegetable allotments and cycle routes already built as part of the green belt have helped break down the "invisible borders" that divide gang territory.
By the end of this year, the green belt aims to employ nearly 5,400 people, the majority of them slum dwellers, including former gang members and single mothers.
Medellin hopes the pathways with their stunning panoramic views will become a major tourist attraction.
But as long as the whiff of marijuana remains in the air and gang members loiter on corners, it's going to take some time for all of Medellin's inhabitants to feel safe enough to venture up to the green belt.