Madison Boulder

The Madison Boulder is one of the largest known glacial erratics in North America and among the largest in the world; it is preserved in the Madison Boulder Natural Area in Madison, New Hampshire. The boulder is a huge granite rock measuring in length, in height above the ground, and in width. It weighs upwards of. A part of the block is buried, probably to a depth of. It was acquired by the state from the Kennett family in 1946. In 1970, Madison Boulder was designated as a National [Natural Landmark] by the National Park Service.