The largest rainforest in the world is the Amazon Rainforest, which spans across several countries in South America, including Brazil, Peru, and Colombia. Covering approximately 5.5 million square kilometers, it's renowned for its immense biodiversity and ecological significance. The Amazon River, the second-longest river in the world, flows through this vast rainforest and supports a myriad of wildlife species, many yet to be discovered. The Amazon plays a crucial role in global climate regulation, acting as a carbon sink and influencing weather patterns, making its preservation critical to combating climate change.