Medellín

city · earth

Colombia's second city, in the narrow Aburrá valley, and the standing example of infrastructure being pushed uphill into settlements that grew without it rather than the reverse. From the early 2000s the municipality pursued what it called social urbanism: cable-car lines, library parks, schools and public space placed deliberately in the poorest and most violent comunas, on the argument that the state's physical presence and a usable commute were the same intervention. The evidence is genuinely mixed and worth stating precisely — a natural-experiment study by Cerdá and colleagues found substantially larger declines in violence in neighbourhoods served by the first Metrocable line than in comparable control neighbourhoods over 2003–2008, while the city's overall homicide decline over the same decades has many causes, including a national security context this Journey does not attempt to disentangle. Since 2016 the city has also run a green-corridor programme, planting connected vegetated routes along streams and roads; the city and its partners report a reduction of about 2°C in the urban heat island, a programme-reported figure rather than an independent attribution study.