The world's largest living organism is a vast underground network of a single species of fungus called Armillaria ostoyae, commonly known as the honey fungus. Located in the Malheur National Forest in Oregon, this organism covers roughly 2,384 acres (965 hectares) and is estimated to be thousands of years old. It primarily grows beneath the soil, spreading its mycelium across a large area and feeding on decaying wood. This expansive and intricate network is not only the largest known living organism on Earth, but it also plays a crucial role in the ecosystem by breaking down organic matter and recycling nutrients.