Tucked between lushly vegetated sand dunes and the Atlantic Ocean, the Mãe Luiza favela spills out from the fringes of Natal, a city of 800,000 people in northeastern Brazil. While the population of Mãe Luiza possesses a strong cultural identity because of its location at the edge of a state nature preserve, it faces challenges common to these dense outer neighborhoods—poverty, inadequate infrastructure, and a dearth of public space.

Herzog & de Meuron and the philanthropic branch of Ameropa, a Swiss fertilizer and grain dealer, partnered with a local organization in 2009 to shape A Vision for Mãe Luiza, a pro bono master plan that seeks to catalyze development in the community. The pioneering building, Areno do Morro, opened April 9.