This is an image of a cross section through a hoof with the shoe still attached and showing how the nail goes through the foot into the white line. It appeared originally in The Hoof Blog, in a post discussing the use of MRI’s for diagnostic purposes and the proper removal of shoes
http://hoofcare.blogspot.com/2011/02/no-farrier-no-mri-diagnostic-imaging.html
This is a fascinating, rarely seen view of the shoe and nails penetrating the hoof. It is remarkable how close the nail is to the edge of the coffin bone. Click on the image for a larger view.