It’s a Saturday afternoon in Jardim Colombo, a favela southwest of São Paulo, and residents have gathered in Fazendinhando Park for a community clean-up event. Volunteers wearing bright pink t-shirts swirl around the hill, sweeping paths, applying rainbow paint to park surfaces and handing out free household supplies as children jump rope and hit a soccer ball on the playing field.

At the center of the action is Ester Carro, a 27-year-old resident. As the professional architect and visionary behind Fazendinhando Park, Carro could easily give orders. Instead, she’s shoulder to shoulder with other volunteers, picking up scraps of trash and pouring paint into roller bins. The only time she puts her brush down is when her seven-year-old son, Ilias, comes to hug her.

In 2017, Carro stood in front of the 2,000 square foot lot, wondering how she would turn the derelict site into the community’s premier recreation space. When Carro was a little girl, the area was a small farm (or fazendinha), where cows and horses grazed. When the man who took care of the land and the animals fell ill, the neighborhood fell into disrepair and the inhabitants began to dump their garbage there. Over time, the mound of rubbish grew to the size of a landfill, with mattresses and other rubbish cascading down the hillside, overflowing into the streets and into neighbors’ homes. The landfill was home to poisonous snakes and scorpions, and the rotting waste produced poisonous methane gas linked to cancer and other serious illnesses.