The Giant Under Your Feet

The mushrooms you see in a forest are only a tiny part of the fungus. Most of it is hidden underground as a web of threads.

Some of these hidden fungi can grow enormous.

In the Blue Mountains of Oregon, a single honey fungus is thought to cover around 3.7 square miles, making it one of the largest living things on Earth.

It is estimated to be thousands of years old, quietly spreading beneath the trees.