<http://schema.org/keywords>
"city, sunset, water, boat, river, motion, nikon, london, colours, thames, vibrant, tripod, d5100, 16:9, widescreen, cinematic"^^<http://www.w3.org/2001/XMLSchema#string>
<https://marketplace.500px.com/photos/14040433/london-boat-sunset-by-alistair-huxley>