<http://schema.org/primaryImageOfPage>
"http://media.mnn.com/assets/images/2012/06/zoo_0.jpg"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/earth-matters/animals/photos/8-of-the-worlds-most-popular-zoos/where-the-wild-things-are>