<http://schema.org/keywords>
"911, tribute in lights, world trade center, new york city, long exposure, memorial, travel, trip, hudson river, night, city, skyline, blue lights"^^<http://www.w3.org/2001/XMLSchema#string>
<https://marketplace.500px.com/photos/15758417/tribute-in-lights-9-11-by-mauricio-fernandez>