<http://schema.org/about>
"10 U.S. parks that are protecting the environment and conserving resources for the future. These 10 parks are taking steps to be the greenest spaces in America."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/earth-matters/wilderness-resources/photos/the-greenest-parks-in-america/astoria-park>