<http://schema.org/about>
"Many of the world's most awe-inspiring caves formed along the shores of oceans and lakes. Here are 9 extraordinarily watery caves from around the globe."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.mnn.com/earth-matters/wilderness-resources/photos/9-wondrous-water-caves/alofaaga-blowholes>