Africa’s Congo Basin, the world’s second-largest rainforest, is also one of the most biodiverse areas, with over 10,000 plant species, 1,000 bird species, and 400 mammal species. In the past few years, the 1.3-million-square-mile forest has been disappearing rapidly because of illegal mining, and the UN predicts two-thirds of it may be completely gone by 2040.