<http://schema.org/image_url>
"http://media.oregonlive.com/oregonian/photo/2013/03/-25cd220775d05346.JPG"^^<http://www.w3.org/2001/XMLSchema#string>
<http://photos.oregonlive.com/4450/gallery/columbia_gorge_wa_03-01-13/index.html>