Violent drug gangs rule the vast slums, or favelas, that are home to nearly a fifth of Rio de Janeiro's population. Away from the slums, the city's beaches, Carnival, and scenery attract tourists from around the world. Foreign businesses are drawn here because of abundant energy supplies and large commercial and financial sectors. Pollution is severe, but investment in fuel based on locally grown sugarcane is lowering emissions. Rio's universities have also created a ""green map"" to show residents how to care for the environment, and city authorities have invested in a massive favela improvement program. ""Rio de Janeiro"" will help readers explore this multifaceted city of seven million. Covering Rio's colonial history and its Native American, European, and African influences, this comprehensive profile examines the impact of the city's incredible growth, and its future prospects.