The tropical rainforest that is the largest in the world is the Amazon Rainforest. Spanning across several countries in South America, including Brazil, Peru, and Colombia, it covers approximately 5.5 million square kilometers (2.1 million square miles). The Amazon Rainforest is renowned for its biodiversity, housing millions of species of plants, animals, and indigenous tribes. It plays a critical role in regulating the Earth's climate and is often referred to as the "lungs of the planet" due to its vast capacity for photosynthesis. Conservation efforts are essential to protect this vital ecosystem from deforestation and climate change.