A mushroom rock, also called rock pedestal or a pedestal rock, is a naturally occurring rock whose shape, as its name implies, resembles a mushroom. The rocks are deformed in a number of different ways: by erosion and weathering, glacial action, or from a sudden disturbance. Mushroom rocks are related to, but different from, yardang andIn contrast to a mushroom rock formed by erosion of a single rock, these mushrooms are a type of balancing rock that formed from two separate rocks, one of which came to rest on top of the other. Typically the uppermost rock was transported and deposited by the slow action of a glacier. The lower part of the rock formation might or might not have also undergone a degree of erosion to accentuate the mushroom shape. Examples of this type of rock are 'Mushroom Rock' in Signal Point National ParkTennessee,[2] and Le Champignon inHuelgoat, France.[3] zeugen.