Photo: Olympic National Park, Washington state USA
This is the world's largest Cedar tree.
Diameter - 20 feet or 6.1 meters
Height - 178 feet or 54.3 meters
Age - estimated at over 1000 years old
Ranking - Listed as the third largest tree in the United States, behind two Redwood trees in California
A 17 mm lens was used and still couldn't fit all of the base into this photo. I walked under this root with 3 feet or a little under 1 meter to spare. A piece of the tree recently broke off and the piece was much larger then most full grown trees. The park service has now built a small fence around the tree with a walking path, I think they have finally realized how special and unique this tree really is, to some it looks like it came out of a horror movie.
Based on my experience, my guess is that this tree got it start as it grew on top of another fallen large tree. Usually the roots are left elevated as the tree below rots to dust over a long period of time.