Some of you may of seen this already, it is huge.

http://i29.tinypic.com/20ra8v7.jpg

It is hard to scale it in this image, but I am guessing from the way this guy zoomed in, it is about 3/4 the size of a football pitch and 3-5 stories high.

YouTube: http://www.youtube.com/watch?v=23Fj9vEc3OM