Retiro is a barrio of Buenos Aires which acts as a border between the upscale and downtrodden. On the South and West sides it's bordered by Puerto Madero and Recoleta respectively, but deeper inside past the bus station and across the train tracks, it's another world. Within half a mile of the Four Seasons and Patio Bullrich (one of the most upscale shopping malls in the city), lies the villa of Retiro. Known as Villa 31, this shantytown is built alongside the train tracks and under the highway. It is a self contained city with dilapidated homes built from found materials, window shops selling grocery items and even local bars. In many cases, there is no street access from outside, no paved roads inside, no sanitation system and no official electric hookups. Villa 31 is only one of hundreds of villas which exist in Buenos Aires, scattered under freeways or along the backsides of towering buildings, once against demonstrating the dichotomy of the city.