With global income disparity at its highest in history, impoverished communities around the world are growing at an impossible rate, leaving hundreds of millions of people living in slum conditions. Slums have been characterized by the U.N. as informal settlements with housing of poor structural quality, insufficient living area, lack of secure tenure, poor access to water, and a dearth of sanitation. Slums have become hotbeds of disease and crime. It is estimated that more than 1 billion people are forced to live in substandard conditions across the globe, according to Homeless International. These are the 10 largest slum areas in the world.