The Amazon rainforest is one of several areas of tropical rainforest around the world. These forests are found only where the correct mix of sun, warmth and rainfall is just right. This combination is commonest along a belt around the world marked by the equator, an imaginary line forming the boundary between the northern and southern hemispheres. The limits of tropical rainforest are within the tropical zone, formed by the two tropic lines, the Tropic of Cancer and Tropic of Capricorn. These are about 23.5 degrees north and south of the equator and represent the farthest north and south where the sun can shine directly overhead rather than at an angle as in temperate zones such as Europe and North America. The Amazon is the largest region of tropical rainforest remaining, while the Congo river basin in Africa is the second largest. They're also the most intact. In Southeast Asia much of the original tropical rainforest is gone, logged for lumber, farming or urban development. Click on the map below to learn more about the main areas of tropical rainforest around the world.