<http://schema.org/about>
"The U.S. showcases some of the most beautiful scenery on earth and duly protects it. Here are the top 10 most popular parks of the National Park Service."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/earth-matters/wilderness-resources/stories/10-most-popular-attractions-of-the-national-park-service>