San Martín is a poor area on the edge of Buenos Aires, not terribly safe but full of life.
Hint: in some places, like favelas, it is helpful to explore and photograph in the early morning, before the young men wake up. You can sometimes feel the energy change when the young men arise in the heat of the day, sloughing off the previous night’s adventures. Mornings are the time for kids and mothers and the elders of a barrio.
I was in Buenos Aires in January, the height of summer, and man, it was hot. Many families and homes had little plastic pools set up with warm water where people could play and cool off, even in the early hours of the morning.