The geographic feature characterized by a large, lush forest is a rainforest. Rainforests are typically found in tropical regions and are known for their high levels of precipitation and biodiversity. They play a crucial role in the Earth's ecosystem by supporting a vast array of flora and fauna, including many species that are not found anywhere else. The Amazon Rainforest, for example, is the largest in the world and is often referred to as the "lungs of the planet" due to its oxygen-producing capabilities.