As soon as you arrive, the roads get bumpier and the air thickens. Almost instantly, the hills — an array of colorful shacks, houses and multi-storied apartment complexes — completely surround you. This is Tijuana, the sixth-largest metropolitan area in Mexico, with an estimated population of 5 million. With only a metal fence marking the border, it is hard to imagine the United States is just on the other side, as most of the city lives in extreme poverty. These pictures were taken on a recent trip to the city of Tijuana. They are a look into the lives we so often forget about, and the injustices we often ignore despite the closeness of the other side.